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14.2.2 Solubility andFermentability
The water solubility and fermentation of inulin by gut microbiota are critical for its
functions. As a soluble ber, inulin dissolves in the gut, forming a gel-like substance
that slows digestion and enhances nutrient absorption (Wan etal. 2020). This pro-
cess not only aids in regulating digestion but also in controlling blood glucose lev-
els, thus contributing to signicant benets for diabetic patients. The fermentation
process leads to the production of SCFAs, which play pivotal roles in maintaining
colon health, immune modulation, and nutrient absorption (Song etal. 2020a; Boets
etal. 2015). These SCFAs, along with other byproducts like lactate, acetate, propio-
nate, butyrate, and gases, contribute to a healthy gut environment by affecting intes-
tinal pH, motility, permeability, and immunity (Song etal. 2020a; Boets etal. 2015).
The production of SCFAs, particularly, has systemic effects on inammation, lipid
synthesis, glucose homeostasis, and energy metabolism (Birkeland etal. 2020).
14.2.3 Chemical Structure andDegree ofPolymerization
The unique chemical structure of inulin, characterized by fructose polymers linked
by β (2 → 1) bonds, endows it with distinct physiological effects. This structure
affects its digestibility, fermentation and overall functionality as a dietary ber. The
DP of inulin inuences its fermentation and solubility, impacting its physiological
effects and health benets (Chen etal. 2024). Inulin with different DPs can have
varied impacts on gut microbiota composition, SCFA production, and mineral
absorption. The integrity of the intestinal barrier and the local immune system are
also inuenced by its structure and fermentability (Sheng et al. 2023). Previous
research has shown that inulin consumption can enhance the proliferative activity of
intestinal stem cells, leading to structural changes in the colon that support its func-
tion (Sheng etal. 2023; Corrêa etal. 2023). This relationship between inulin and the
physical structure of gut highlights the intricate ways in which inulin contributes to
maintaining gut integrity and overall well-being.
14.3 Synergistic Effects withOther Dietary Components
Inulin’s interaction with other dietary components can enhance its health benets.
For instance, the combined intake of inulin and protein or other bers may have
synergistic effects on gut health, immune function, and nutrient metabolism
(Tawck etal. 2022; Lunken etal. 2017). This versatility makes inulin a valuable
ingredient in various processed foods, including protein bars, yogurts, beverages,
and desserts, offering a practical way to enhance dietary ber intake and support
health (Abed etal. 2016; Shoaib etal. 2016).
14 Therapeutic Role ofInulin inDisease Management
308
14.4 Therapeutic Potential ofInulin
Inulin, a type of dietary ber found in many plants such as chicory root, garlic,
onions, and asparagus, has garnered attention for its numerous health benets. This
soluble ber acts as a prebiotic, meaning it feeds the benecial bacteria in the gut,
leading to improved health outcomes. Inulin’s therapeutic potential spans from
enhancing digestive health to inuencing positive outcomes in metabolic health
markers (Kaur etal. 2021; Mensink etal. 2015; Tawck etal. 2022). As a pivotal
prebiotic, inulin contributes to a variety of health benets, including but not limited
to infant nutrition, digestive wellness, bone mineralization, fatty liver disease miti-
gation, obesity management, blood sugar and lipid metabolism regulation, immune
system enhancement, and colon cancer prevention. In the following sections, some
of the major therapeutic applications of inulin are provided in details (Valcheva
etal. 2019; Wang etal. 2019; Tawck etal. 2022).
14.5 Inulin asaPrebiotic
The gut microbiota plays a crucial role in human health, directing a complex sym-
phony that resonates beyond digestive processes to inuence the immune system,
mental health, and susceptibility to chronic diseases. Inulin serves as an essential
food source for benecial gut bacteria, such as Bidobacterium and Faecalibacterium,
stimulating their growth and activity. For instance, Gibson etal. conducted a dietary
intervention double-blind cross-over study with 32 healthy adults (Costabile etal.
2010). The individuals were randomly divided into two groups: placebo (consum-
ing maltodextrin) and other group consuming very-long-chain inulin (VLCI),
derived from globe artichoke (Cynara scolymus). After 3weeks of 10g/day inges-
tion followed by 3-week washout period, compared to the placebo, individuals con-
suming VLCI showed a signicant increase in the number of fecal bidobacteria
and lactobacilli. This process of selective stimulation leads to a more balanced and
diverse gut microbiota, which is fundamental for maintaining overall health. The
increase in benecial bacteria, such as Bidobacteria, enhances the gut barrier func-
tion, reduces pathogen colonization, and supports the immune system. Inulin-type
fructans are selectively fermented by benecial microbes in the colon and are resis-
tant to digestion by human enzymes. This selective fermentation process not only
increases the diversity and population of health-promoting bacteria but also sup-
presses pathogenic groups, showcasing pivotal role of inulin in gut health (Ito etal.
2011; Ji etal. 2024).
The health benets of inulin extend through both direct and indirect mechanisms
(Table14.1). Directly, inulin consumption can reduce caloric intake by serving as a
fat and sugar replacer, exhibit antioxidant activities, and exert anti-inammatory
effects (Liu etal. 2017). These immediate impacts of inulin consumption demon-
strate its potential in reducing plasma lipid and cholesterol levels. Indirectly, inu-
lin’s effect on the population and diversity of colon bacteria stimulates the production
of benecial SCFAs by gut microbiota, enhancing gut barrier function and reducing
A. Guglani et al.
309
Table 14.1 Mechanism of inulin as prebiotic
Mechanism
of action
Effect
Description
Direct
action
Caloric intake
reduction
Inulin is resistant to human digestive enzymes and not even
absorbed by the small intestine; therefore, it potentially
reduces overall caloric intake (Sheng etal. 2023)
Antioxidant
activity
Inulin exhibits protective action against oxidative damages
to digestive organs by neutralizing free radicals (Pasqualetti
etal. 2014)
Anti-
inammatory
effects
It offers protective effects against inammation,
contributing to gut health and potentially reducing the risk
of chronic diseases (Birkeland etal. 2020)
Lipid and
cholesterol
regulation
It plays a role in reducing plasma lipid and cholesterol
levels, supporting cardiovascular health (Williams 1999;
Hoving etal. 2018)
Indirect
action
Gut microbiota
modulation
It inuences the population and diversity of colon bacteria,
promoting the growth of benecial bacteria over harmful
ones (Valcheva etal. 2019; Pasqualetti etal. 2014)
Enhancement of
gut barrier
It stimulates the production of benecial SCFAs by gut
microbiota, enhancing gut barrier function and reducing
pathogen colonization (Pasqualetti etal. 2014)
Immune system
support
By promoting the growth of benecial bacteria in the gut,
inulin enhances the differentiation and activity of regulatory
T cells, to improve overall immune homeostasis (Sheng
etal. 2023; Tawck etal. 2022)
pathogen colonization (Song etal. 2020a; van der Beek etal. 2018; Tawck etal.
2022). By selectively fostering the growth of benecial bacterial groups over harm-
ful ones, inulin signicantly inuences human health. The benecial bacterial
groups particularly targeted by inulin include Lactobacilli (e.g., Lactobacillus aci-
dophilus, L. casei, L. delbrueckii), Bidobacteria (e.g., Bidobacterium bidum,
B. adolescentis, B. longum, B. infantis), and Streptococci (e.g., Streptococcus sali-
varius subspecies thermophilus, S. lactis) (van der Beek etal. 2018; Yin etal. 2023).
Studies have shown that inulin supplementation can markedly alter the bacterial
composition in the human colon, signicantly increasing the levels of bidobacteria
while reducing the presence of harmful bacteria (Teferra 2021; Ramirez-Farias
etal. 2009).
14.6 Impact onGut Microbiota Composition
Inulin is celebrated for its substantial impact on digestive wellness. Its prebiotic
nature supports the proliferation of benecial gut bacteria such as Bidobacteria
and Lactobacilli, enhancing gut health and function (Tawck et al. 2022). This
increased microbial diversity is associated with improved bowel regularity and a
reduced risk of gastrointestinal disorders, including constipation and irritable bowel
syndrome (IBS) (de Almeida Gualtieri et al. 2013; Hughes et al. 2022). The
14 Therapeutic Role ofInulin inDisease Management
310
consistent consumption of inulin results in notable changes in the gut microbiota
composition, primarily marked by an increased prevalence of benecial bacteria
(Valcheva etal. 2019). In this regard, a meta-analysis of nine studies in human
adults by Montassier etal. reported that inulin consumption caused an increase in
abundance of Bidobacteria while relatively abundance of Bacteroides was found
to be reduced (Le Bastard etal. 2020). Such variation in microbial populations is
signicantly affected by the physicochemical properties of inulin, including its
degree of polymerization and solubility, which directly inuence the diversity and
abundance of SCFAs produced during fermentation (Song etal. 2020a). Inulin, as
an indigestible ber, is subject to fermentation by the gut microbiota within the
large intestine. This fermentation leads to an increase in the production of benecial
SCFAs and other metabolites. The resultant higher concentration of SCFAs helps to
suppress potentially harmful bacteria, such as Bacteroides, fostering a more favor-
able environment for gut health (Ramirez-Farias etal. 2009; Vinelli etal. 2022). The
alteration of gut microbiota composition, potentiates immunological function by
augmenting the synthesis of the cytokine IL-22 and activity of intestinal stem cells,
leading to the regeneration and restitution of the colon epithelium (Tawck etal.
2022). In particular, the enhanced barrier function is essential for preventing the
entry of pathogens and maintaining immune homeostasis. Moreover, the shift in
microbial composition associated with inulin intake contributes to a range of health
benets. These include improved bowel regularity, a decreased risk of gastrointesti-
nal infections, and potential protective effects against certain types of cancer (Vinelli
etal. 2022; Li etal. 2021; Wang etal. 2020).
14.7 Enhancement ofDigestive Processes
The metabolic advantages of inulin intake are profound. Studies have demonstrated
its role in glycemic control, showing that inulin can lower fasting blood glucose
levels and improve insulin sensitivity, making it a valuable dietary addition for indi-
viduals with or at risk of diabetes (Wang etal. 2019; Liu etal. 2017; Weitkunat etal.
2017). Furthermore, inulin helps in managing lipid metabolism, reducing triglycer-
ides and low-density lipoprotein (LDL) cholesterol levels, which are crucial for
cardiovascular health (Hoving etal. 2018; Li etal. 2021).
The intake of inulin has been demonstrated to have several benecial impacts on
digestive processes through multiple mechanisms. It is fermented by gut microbiota
into SCFAs, such as butyrate, propionate, and acetate, which have various positive
effects on gut health. These SCFAs can help to lower the pH in the gut, which can
inhibit harmful bacteria and improve mineral absorption, such as calcium and mag-
nesium (Song etal. 2020a). This acidication supports a healthy colon lining and
may reduce the risk of colon cancer (Valcheva etal. 2019). Additionally, inulin has
been associated with increased stool bulk and frequency, which helps in preventing
constipation (Corrêa etal. 2023; Guarino etal. 2020). It also inuences the hor-
monal regulation of appetite and glucose homeostasis by stimulating the release of
peptides like peptide YY and glucagon-like peptide-1 (GLP-1) from
A. Guglani et al.
311
enteroendocrine cells (Kaur et al. 2021; Wang et al. 2019; Li et al. 2021). The
immunomodulatory effects of inulin are signicant, as it has been observed to regu-
late glucose, lipid, and amino acid metabolism, as well as exert benecial effects on
intestinal immune functions. Its fermentation by the gut microbiota also leads to the
production of metabolites with anti-inammatory capabilities (Hoving etal. 2018).
This implies potential roles for inulin in the management of conditions like meta-
bolic syndrome, inammatory bowel disease, and other diseases associated with
intestinal inammation and dysbiosis (Sheng etal. 2023). Furthermore, inulin has
been shown to stimulate the proliferation of intestinal cells, contributing to the
maintenance and repair of the gut lining, which is essential for gut health and the
prevention of diseases like inammatory bowel disease (Du etal. 2024). The exten-
sive ways in which inulin benets gut functionality highlight its essential role in
maintaining digestive health and contributing to overall well-being. Incorporating
foods or supplements rich in inulin into our diet is a proactive measure to not only
boost digestive health but also to reinforce our defense mechanisms against various
health conditions.
14.8 Immune-Modulatory Effects
Inulin’s ability to modulate the immune system stems from its impact on gut
microbiota and the production of SCFAs. These SCFAs have anti-inammatory
properties, enhancing immune function and potentially lowering the risk of
chronic diseases such as colorectal cancer (Ji etal. 2024; Song etal. 2024). In the
following subsections, we will delve into some of major effects of inulin on the
immune system.
14.8.1 Effect ontheImmune System
Inulin has been shown to have several immunomodulatory effects, impacting both
the gut immune cells and the systemic immune function. The fermentation of inulin
by the gut microbiota leads to the production of SCFAs, which contribute to main-
taining the integrity of the intestinal barrier by promoting the expression of tight
junction proteins such as zonula occludens-1, claudin-1, and occludin. These pro-
teins are essential in preserving the gut barrier against pathogens and promoting
immune tolerance by reducing inammatory responses. Moreover, inulin has been
found to stimulate the secretion of mucin and secretory immunoglobulin A (IgA) in
the ileum, which plays a key role in forming a protective mucosal barrier and limit-
ing the immunogenicity of antigens. It also promotes the secretion of cytokine
IL-22, which enhances intestinal homeostasis and barrier function (Sheng et al.
2023; Pujari and Banerjee 2021).
Watzl etal. explored the immunomodulatory effects of inulin (Watzl etal. 2005).
In the study, healthy adult volunteers were given a diet supplemented with inulin,
and their immune parameters were monitored over several weeks. The study
14 Therapeutic Role ofInulin inDisease Management
312
revealed the increased natural killer (NK) cells activity and a higher regulatory T
(Treg) cells population demosntrating signicant immunomodulatory effects. The
study also found an upregulation of anti-inammatory cytokines (IL-10), and a
reduction in pro-inammatory cytokines (TNF-α and IL-6) indicating immune reg-
ulation. Interestingly, the study also reported that the effects of inulin were dose-
dependent; with moderate doses, the immune regulation and gut barrier function
were improved, while the higher doses enhanced the pro-inammatory markers lev-
els. This study has indicated that the effects of inulin on the immune system can
vary with the dose, while moderate amounts may offer protective benets, higher
doses could potentially lead to adverse effects like increased levels of inammation-
related factors. These ndings suggest the therapeutic potential of inulin for condi-
tions related to immune dysregulation and inammation, such as food allergies,
metabolic syndrome, and inammatory bowel disease (Watzl etal. 2005).
On the cellular level, inulin impacts various immune cells. SCFAs play a crucial
role in modulating the metabolic pathways and genetic expression of T cells (Pujari
and Banerjee 2021). It regulates the differentiation and proliferation of immune
cells such as T regulatory (Treg) cells, which are essential for maintaining immune
tolerance and preventing excessive inammatory responses (Yanckello etal. 2022a).
These Treg cells limit the immune response and are key to avoiding overwhelming
inammation that can lead to tissue damage. SCFAs can reprogram metabolic activ-
ity T cells, impacting the balance between effector T cells and Treg cells. In addition
to modulating gut immunity, inulin also impacts systemic immune responses. The
SCFAs, once absorbed into the bloodstream, can inuence immune cells throughout
the body, further underlining the systemic impact of inulin (Corrêa etal. 2023).
14.8.2 Augmentation ofImmune Responsiveness
Correa etal. investigated the interactions between an inulin-rich diet, gut microbi-
ota, and immune cells on healthy adult volunteers (Corrêa etal. 2023). The study
found that the inulin supplementation enhances the proliferation of benecial gut
microbiota, including Lactobacilli and Bidobacteria, and leads to increase in the
production of SCFAs, which enhance the immune responsiveness, by stimulating
the proliferation of T regulatory (Treg) cells, which are essential for maintaining
immune tolerance and prevention of excessive inammatory responses. Further, the
study observed that these microorganisms exert a stimulatory effect on the immune
system, leading to increased production of immunoglobulins and enhanced phago-
cytic activity, while promoting the release of cytokines that direct immune cells to
sites of infection, thereby strengthening the defense mechanisms of body. The
SCFAs have shown to induce the expression of antimicrobial peptides, enhance
mucosal immunity by increasing secretory IgA levels, and even promote IL-22
secretion by innate lymphoid cells, contributing to the maintenance of the intestinal
barrier and immunological homeostasis (Sheng etal. 2023; Corrêa etal. 2023).
A. Guglani et al.
313
14.8.3 Contribution toaBalanced Immune Profile
Sheng et al. studied the immunomodulatory effects of inulin and its intestinal
metabolites by administering an inulin-rich diet to a group of healthy adult volun-
teers over several weeks (4weeks and 3months’ time points) (Sheng etal. 2023).
The ndings revealed that SCFAs signicantly enhance the proliferation of Treg
cells while reducing the numbers of pro-inammatory Th17 cells. This modulation
of T-cell responses helps suppress intestinal inammation and promotes a balanced
immune prole. Additionally, the study found that SCFAs induced the expression of
antimicrobial peptides, enhanced mucosal immunity by increasing secretory IgA
levels, and promoted IL-22 secretion by innate lymphoid cells. These actions col-
lectively contribute to the maintenance of the intestinal barrier and overall immuno-
logical homeostasis. The systemic effects of SCFAs were further evidenced by the
modulation of immune responses in peripheral tissues, highlighting the extensive
immunomodulatory potential of inulin (Sheng etal. 2023). These actions demon-
strate the potential of inulin for modulating immune responses and providing pro-
tection against allergies and autoimmune diseases.
14.9 Mineral Absorption andSkeletal Integrity
Inulin promotes the absorption of minerals, notably calcium and magnesium, which
are essential for bone health. Increased mineral absorption can lead to improved
bone density, offering potential benets in the prevention and management of osteo-
porosis (Whisner and Castillo 2018; Scholz-Ahrens and Schrezenmeir 2002). In the
following subsections, a detailed description of inulin is provided.
14.9.1 Inulin’s Role inMineral Absorption
Scholz-Ahrens etal. reported that the inulin signicantly contributes to the absorp-
tion of minerals in the digestive system in rats (Scholz-Ahrens and Schrezenmeir
2002). The study demonstrated that the inulin fermentation by intestinal microbiota
leading to the production of SCFAs that lower the pH in the colon, enhancing the
solubility and, therefore, facilitate the absorption of minerals such as calcium and
magnesium. Efcient mineral absorption plays a vital role in numerous physiologi-
cal functions, including enzymatic reactions and nerve transmission. This is particu-
larly important during the early years of life and adolescence, but also remains
relevant in preventing bone density loss in older adults. The study highlights the
inulin potential as a dietary supplement to support mineral metabolism and overall
health. Therefore, inulin plays an important role in promoting bone health and pre-
vents mineral deciencies.
14 Therapeutic Role ofInulin inDisease Management
314
14.9.2 Implications forBone Health
The implications of inulin for bone health are substantial due to its role in improv-
ing mineral uptake. Minerals like calcium are foundational to bone structure and
strength, and their increased absorption mediated by inulin is directly linked to bone
health. By improving calcium and magnesium absorption, it contributes to the
development and maintenance of bone density and overall skeletal integrity. This
can have signicant implications for bone health, contributing to stronger bones and
a potential reduction in the risk of osteoporosis. Experiments have been conducted
with the animal models and human participants to explore the impact of inulin on
bone health (Whisner and Castillo 2018; Weaver 2005; Bosscher etal. 2006; Coxam
2007). The studies have shown that the inulin-enriched diet led to a signicant
increase in the absorption of calcium and magnesium, due to the production of
SCFAs. The SCFAs lower the colon pH that increases the solubility of minerals,
thus facilitating their absorption and contributing to improved bone mineral density
and skeletal integrity (Bosscher etal. 2006). Furthermore, the studies have shown
that inulin can aid in optimizing bone mineral density, which is particularly impor-
tant during periods of rapid growth such as adolescence and in the prevention of
age-related bone loss (Weaver 2005; Bosscher etal. 2006; Coxam 2007).
14.9.3 Addressing Bone-Related Disorders
The benecial effects of inulin on mineral absorption may extend to the prevention
and management of bone-related disorders such as osteoporosis, which is character-
ized by reduced bone density and an increased risk of fractures (Bosscher et al.
2006; Bakirhan and Karabudak 2021). Adequate calcium absorption is important in
mitigating the risk of developing osteoporosis and other bone density-related condi-
tions. Holloway etal. conducted a double-blind, placebo-controlled study with 31
postmenopausal women to determine the effects of oligofructose-enriched inulin on
the intestinal absorption of minerals and bone turnover markers in postmenopausal
women (Holloway etal. 2007). In the study, subjects were given 5g of the oligo-
fructose from chicory plus long-chain inulin-enriched with oligofructose or placebo
(matodextrin) for 6weeks followed by a 6-week washout period. The researchers
noted a signicant increase in calcium and magnesium absorption in the group
ingesting inulin-enriched diet by the production of SCFAs. Additionally, a notable
increase in serum osteocalcin levels and reduction in urinary deoxypyridinoline lev-
els were also overserved. The increase in osteocalcin levels indicates improved bone
formation. These ndings suggest that oligofructose-enriched inulin can improve
bone health by enhancing mineral absorption and positively inuencing bone turn-
over, thereby offering a potential dietary intervention to help prevent osteoporosis in
postmenopausal women. Therefore, inulin, by supporting mineral homeostasis and
bone mineral density, may offer a dietary approach to addressing these disorders.
Regular intake of inulin-rich foods or supplements could be an effective strategy in
preventing and managing conditions like osteopenia and osteoporosis, particularly
A. Guglani et al.
315
among populations at higher risk such as postmenopausal women (Weaver 2005;
Holloway etal. 2007).
14.10 Gut-Brain Connection andCognitive Health
Emerging research suggests inulin may also inuence mental well-being and cogni-
tive functions through the modulation of gut-brain axis (Tawck et al. 2022;
Yanckello etal. 2022a,b; Baldi et al. 2021). The modulation of gut microbiota by
inulin could have far-reaching effects on mood, anxiety, and cognitive health,
although further research is needed in this area (Cryan and O’Mahony 2011; Guo
etal. 2022; Ahmadi etal. 2019). Researchers have examined to understand the role
of probiotics and prebiotics in modulating the gut-brain axis (Ahmadi etal. 2019;
Ansari etal. 2023). The ndings reveal that the administration of specic probiotics
and prebiotics altered the gut microbiota composition, leading to the production of
SCFAs having neuroactive properties (Chang etal. 2023). Furthermore, it is indi-
cated that the modulation of the gut-brain axis could enhance the production of
neurotransmitters such as gamma-aminobutyric acid (GABA) and serotonin, which
are important for mood regulation and cognitive function (Ansari et al. 2023).
Overall, the gut-brain connection is a fascinating and complex bidirectional com-
munication system between the gastrointestinal tract and the central nervous system
(CNS). This bidirectional pathway involves hormonal, immunological, and neural
mechanisms. The gut microbiota inuences brain function and behavior through
these mechanisms. This connection not only helps regulate basic physiological pro-
cesses but also has a profound impact on cognitive health and overall well-being
(Ansari etal. 2023; Fekete etal. 2024). Impact of inulin on cognitive health is dis-
cussed in more details in the following subsections.
14.10.1 Impact ontheGut-Brain Axis
The gut-brain axis is a bidirectional communication network that involves direct
and indirect pathways between cognitive and emotional centers in the brain and
peripheral intestinal functions (Baldi etal. 2021; Fekete etal. 2024). This commu-
nication network includes the CNS, the enteric nervous system, the autonomic ner-
vous system, and the hypothalamic-pituitary-adrenal axis. The presence of inulin in
the diet is known to change the composition of the gut microbiota, increase the
production of benecial metabolites like SCFAs, and reduce the presence of patho-
genic bacteria (Corrêa etal. 2023). These changes in the gut microbiome can have
profound effects on the gut-brain axis, through the production of neurotransmitters,
immune system modulation, and the maintaining the integrity of the gut barrier (Du
etal. 2024; Guo etal. 2022). The production of neurotransmitters by gut bacteria is
an important aspect of the gut-brain axis, which is the bidirectional communication
pathway between the gastrointestinal tract and the CNS (Appleton 2018). Gut bac-
teria contribute to the production of various neurotransmitters, such as
14 Therapeutic Role ofInulin inDisease Management
316
gamma-aminobutyric acid (GABA), serotonin, dopamine, and norepinephrine
(Dicks 2022). These neurotransmitters can signicantly inuence brain function,
affecting mood, cognition, and overall neurological health. The gut bacteria
Lactobacillus and Bidobacterium produce GABA, which prevents the overexcite-
ment of the CNS (Dicks 2022). In addition, gut microbiota can also inuence sero-
tonin production by modulating the tryptophan levels and metabolize the tryptophan
directly to serotonin (Mhanna etal. 2024). This modulation of tryptophan and sero-
tonin by gut microbiota has implications for various CNS and gastrointestinal func-
tions, including mood regulation and gut motility (Dicks 2022). SCFAs can
indirectly affect vagus nerve function through gut-brain signaling pathways. These
SCFAs can interact with the gut lining and through the vagus nerve affecting the
brain functions such as inammation control and neurotransmitter production.
Therefore, the gut microbiota can have a profound impact on the CNS through the
production of neurotransmitters and other metabolites, inuencing a wide range of
brain functions and potentially contributing to the pathogenesis or treatment of neu-
rological and psychiatric disorders including anxiety, depression, autism spectrum
disorder, and Alzheimer’s disease (Silva etal. 2020; Dalile etal. 2019).
14.11 Short-Chain Fatty Acids andNeuroprotection
Fekete etal. conducted a comprehensive review to analyze existing literature and
experimental data to explore the inuence of dietary supplements on cognitive func-
tions by interacting with gut microbiota (Fekete etal. 2024). The article summarizes
that dietary supplements (prebiotics, probiotics, and symbiotics) can signicantly
alter the gut microbiota composition (Li etal. 2023). This alteration leads to the
production of neuroactive metabolites and neurotransmitters like serotonin and
GABA.These metabolites play a prominent role in maintaining gut health, modu-
lating immune responses, and providing energy to colon cells. Beyond their local
effects in the gut, SCFAs can cross the blood-brain barrier and inuence brain func-
tion and development through stimulating the memory and synaptic plasticity, inu-
ence the release of neurotransmitters, and protect the blood-brain barrier from
oxidative stress (Cheng etal. 2024). It is also reported that dietary supplements
including inulin could enhance cognitive health by reducing inammation, improv-
ing gut barrier function, and modulating the immune response (Silva etal. 2020; Li
etal. 2023; Hutchinson etal. 2023). Moreover, SCFAs have been shown to have
neuroprotective effects, potentially reducing the risk of neurodegenerative diseases.
These effects highlight the importance of a ber-rich diet in supporting cognitive
health through the production of SCFAs (Fekete etal. 2024; Silva etal. 2020).
A. Guglani et al.