The Role of Gastrointestinal Microbiota in Functional Dyspepsia: A Review

Menthacarin, a proprietary combination of peppermint and caraway oil, alters cultured human fecal microbiota composition, resulting in increased SCFA production

Background

Disruptions in the gut microbiota metabolism may contribute to the pathophysiology of gut-brain interaction disorders, and correction of intestinal dysbiosis is considered a promising therapeutic approach. Menthacarin, a proprietary fixed combination of Mentha x piperita L. and Carum carvi L. essential oils, is used clinically for the treatment of functional dyspepsia and irritable bowel syndrome. Rodent model data indicate that treatment effects of Menthacarin on visceral hypersensitivity could be mediated via the normalization of gut dysbiosis. However, the impact of Menthacarin on human bacterial gut microbiota has not yet been studied.

Aim

The aim of the present study was to assess whether Menthacarin affects the composition and metabolic activity of human fecal microbiota.

Methods

Fecal slurry samples from 10 healthy volunteers were cultivated for 36 h under anoxic conditions with and without Menthacarin. Relative bacterial abundance at the phylum and genus levels was evaluated using 16S rRNA metagenomic analysis. Short-chain fatty acids (SCFAs) in the supernatants were measured using the LC-MS technology.

Results

Menthacarin induced robust changes in microbial composition at both the phylum and genus levels among the 10 donor microbiomes. The relative abundance of Firmicutes (+13.6 ± 8.6%) and Actinobacteria (+54.9 ± 47.6%) significantly increased, whereas that of Bacteroidetes (-27.7% ± 21.9%) and Proteobacteria (-25.7% ± 12.3%) significantly decreased in the presence of Menthacarin. At the genus level, the most notable changes were significant increases in Bifidobacterium (+105.1 ± 78.4%) and several SCFA-producing genera accompanied by a significant decrease in genera containing members involved in pro-inflammatory processes. In addition, Menthacarin significantly increased the levels of several SCFAs, namely, propionate, butyrate, isobutyrate, valerate, and isovalerate.

Conclusion

Menthacarin alters the microbiota composition and enhances SCFA production in human microbiota samples under in vitro conditions. These effects may contribute to the clinical benefits observed with Menthacarin treatment.

Maslinic acid improves mitochondrial function and inhibits oxidative stress and autophagy in human gastric smooth muscle cells

Functional dyspepsia (FD) is a chronic disease that occurs in the gastroduodenal region and significantly impacts human health. Maslinic acid (MA), a pentacyclic triterpene acid, is the primary bioactive ingredient in Chinese medicinal herbs such as hawthorn, which exhibits beneficial impacts on the regulation of various disease progressions. However, the specific functions and associated pathways of MA in FD progression remain unclear and require further investigation. In this work, it was demonstrated that MA enhanced the cell viability of human gastric smooth muscle cells (HGSMCs). In addition, the mitochondrial dysfunctions induced by carbonyl cyanide 3-chlorophenylhydrazone (CCCP) were rescued after MA treatment. Furthermore, autophagy was increased following CCCP treatment, but this phenomenon was counteracted after MA treatment. The oxidative stress, elevated after CCCP treatment, was alleviated following MA addition. Finally, the AMPK/SIRT1 pathway was suppressed after CCCP stimulation but was re-activated after MA treatment. In conclusion, it was uncovered that MA accelerated HGSMC viability and improved mitochondrial function, inhibited autophagy, alleviated oxidative stress, and stimulated the AMPK/SIRT1 pathway. This discovery may offer new insight into the therapeutic effects of MA in FD progression.

Microbiota modulation in disorders of gut-brain interaction

Disorders of gut-brain interaction (DGBI) are common chronic conditions characterized by persistent and recurring gastrointestinal symptoms triggered by several pathophysiological factors, including an altered gut microbiota. The most common DGBI are irritable bowel syndrome (IBS), functional constipation (FC) and functional dyspepsia (FD). Recently, a deep understanding of the role of the gut microbiota in these diseases was possible due to multi-omics methods capable to provide a comprehensive assessment. Most of the therapies recommended for these patients, can modulate the gut microbiota such as diet, prebiotics, probiotics and non-absorbable antibiotics, which were shown to be safe and effective. Since patients complain symptoms after food ingestion, diet represents the first line therapeutic approach. Avoiding dietary fat and fermentable oligosaccharides, disaccharides, monosaccharides, and polyols, and increasing the number of soluble fibers represent the therapeutic choices for FD, IBS and FC respectively. Probiotics, as a category, have been employed with good results in all the abovementioned DGBI. Rifaximin has been shown to be useful in the context of bowel related disorders, although a recent trial showed positive results for FD. Fecal microbiota transplantation has been tested for IBS and FC with promising results. In this review, we will briefly summarize the current understanding on dysbiosis and discuss microbiota modulation strategies to treat patients with DGBI.

The causality between gut microbiota and functional dyspepsia: A two-sample Mendelian randomization analysis

To investigate the potential link between gut microbiota and functional dyspepsia (FD). Genome-wide association studies (GWAS) of gut microbiota and FD were used in Mendelian randomization (MR) research. Using the GWAS of 18,340 people, instrumental variables related to gut microbiota as an exposure factor were identified. In a GWAS investigation, 189,695 control individuals and 4376 FD patients were included as outcome variables. The primary analysis technique was inverse variance weighted analysis. The reliability of MR analysis results is tested using sensitivity analysis. Two-sample Mendelian randomization analysis revealed the presence of 7 gut microbiota associated to FD. In the inverse variance weighted analysis method, Order Erysipelotrichales (odds ratio (OR): 1.301; 95% confidence interval (CI): 1.016, 1.665; P = .037), Family Erysipelotrichales (OR: 1.301; 95% CI: 1.016, 1.665; P = .037), Genus Haemophilus (OR: 1.236; 95% CI 1.059, 1.442; P = .007), Genus Ruminiclostridium 9 (OR: 1.422; 95% CI: 1.078, 1.877; P = .013), Genus Lachnospiraceae NK4A 136 group (OR: 1.297; 95% CI: 1.059, 1.589; P = .012) was positively associated with FD. Class Gammaproteobacteria (OR: 0.705; 95% CI: 0.522, 0.952; P = .022) and Genus Erysipelatoclostridium (OR: 0.747; 95% CI: 0.628, 0.888; P = .001) were found to be inversely related to FD. There was no evidence of pleiotropy or heterogeneity in the sensitivity analysis. Our research provides evidence for a possible link between FD and a number of gut microbiota. The role that gut microbiota plays in the development of FD requires more investigation.

Unlocking the power of short-chain fatty acids in ameliorating intestinal mucosal immunity: a new porcine nutritional approach

Short-chain fatty acids (SCFAs), a subset of organic fatty acids with carbon chains ranging from one to six atoms in length, encompass acetate, propionate, and butyrate. These compounds are the endproducts of dietary fiber fermentation, primarily catalyzed by the glycolysis and pentose phosphate pathways within the gut microbiota. SCFAs act as pivotal energy substrates and signaling molecules in the realm of animal nutrition, exerting a profound influence on the intestinal, immune system, and intestinal barrier functions. Specifically, they contibute to 60-70% of the total energy requirements in ruminants and 10-25% in monogastric animals. SCFAs have demonstrated the capability to effectively modulate intestinal pH, optimize the absorption of mineral elements, and impede pathogen invasion. Moreover, they enhance the expression of proteins associated with intestinal tight junctions and stimulate mucus production, thereby refining intestinal tissue morphology and preserving the integrity of the intestinal structure. Notably, SCFAs also exert anti-inflammatory properties, mitigating inflammation within the intestinal epithelium and strengthening the intestinal barrier's defensive capabilities. The present review endeavors to synthesize recent findings regarding the role of SCFAs as crucial signaling intermediaries between the metabolic activities of gut microbiota and the status of porcine cells. It also provides a comprehensive overview of the current literature on SCFAs' impact on immune responses within the porcine intestinal mucosa.

Comparison of the effects of Amomum tsaoko and its adulterants on functional dyspepsia rats based on metabolomics analysis

Amomum tsaoko (AT) is commonly used in clinical practice to treat abdominal distension and pain. It is also a seasoning for cooking, with the functions of appetizing, invigorating the spleen, and being digestive-promoting. Amomum tsaoko (AT) has three adulterants, Amomum paratsaoko (AP), Amomum koenigii (AK), and Alpinia katsumadai Hayata, because of the confusion in historical classics regarding recorded sources as well as the near geographic distribution and fruit morphological similarities. In this study, we established a functional dyspepsia (FD) rat model and then treated it with the corresponding medicinal solutions AT, AP, AK, and AKH. The gastric emptying rate, intestinal propulsion rate, serum biochemical indicators, histopathological changes, and fecal metabolism were measured. The efficacy and mechanism of AT, AP, AK, and AKH in the treatment of FD were compared. Fecal metabolomics revealed that 20 potential biomarkers were involved in seven significant metabolic pathways in FD rats. These pathways include ubiquinone and other terpenoid-quinone biosynthesis, glycerophospholipid metabolism, tyrosine metabolism, primary bile acid biosynthesis, purine metabolism, folate biosynthesis, and amino sugar and nucleotide sugar metabolism. AP regulates 6 metabolic pathways, 5 metabolic pathways affected by AT, 4 metabolic pathways affected by AK, and 2 metabolic pathways affected by AKH.The above results suggest that the different effects of AT, AP, AK, and AKH on FD rats may be due to their different regulatory effects on the metabolome.

Duodenal microbiota dysbiosis in functional dyspepsia and its potential role of the duodenal microbiota in gut-brain axis interaction: a systematic review

Background and aims

Functional dyspepsia (FD) is a common gastrointestinal disorder associated with brain-gut interaction disturbances. In recent years, accumulating evidence points to the duodenum as a key integrator in dyspepsia symptom generation. Investigations into the pathological changes in the duodenum of FD patients have begun to focus on the role of duodenal microbiota dysbiosis. This review summarizes duodenal microbiota changes in FD patients and explores their relationship with gut-brain interaction dysregulation.

Methods

Ten databases, including PubMed, MEDLINE, and the Cochrane Library, were searched from inception to 10th October 2023 for clinical interventional and observational studies comparing the duodenal microbiota of FD patients with controls. We extracted and qualitatively summarized the alpha diversity, beta diversity, microbiota composition, and dysbiosis-related factors.

Results

A total of nine studies, consisting of 391 FD patients and 132 non-FD controls, were included. The findings reveal that the alpha diversity of the duodenal microbiota in FD patients does not exhibit a significant difference compared to non-FD controls, although an upward trend is observed. Furthermore, alterations in the duodenal microbiota of FD patients are associated with the symptom burden, which, in turn, impacts their quality of life. In FD patients, a considerable number of duodenal microbiota demonstrate a marked ascending trend in relative abundance, including taxa such as the phylum Fusobacteria, the genera Alloprevotella, Corynebacterium, Peptostreptococcus, Staphylococcus, Clostridium, and Streptococcus. A more pronounced declining trend is observed in the populations of the genera Actinomyces, Gemella, Haemophilus, Megasphaera, Mogibacterium, and Selenomonas within FD patients. A negative correlation in the relative abundance changes between Streptococcus and Prevotella is identified, which correlates with the severity of symptom burden in FD patients. Moreover, the alterations in specific microbial communities in FD patients and their potential interactions with the gut-brain axis merit significant attention.

Conclusion

Microbial dysbiosis in FD patients is linked to the onset and exacerbation of symptoms and is related to the disorder of gut-brain interaction. Larger-scale, higher-quality studies, along with comprehensive meta-omics research, are essential to further elucidate the characteristics of the duodenal microbiota in FD patients and its role in FD pathogenesis.Systematic review registration: CRD42023470279, URL: https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42023470279.

Improvement of functional dyspepsia with Suaeda salsa (L.) Pall via regulating brain-gut peptide and gut microbiota structure

PURPOSE

The traditional Chinese herbal medicine Suaeda salsa (L.) Pall (S. salsa) with a digesting food effect was taken as the research object, and its chemical composition and action mechanism were explored.

METHODS

The chemical constituents of S. salsa were isolated and purified by column chromatography, and their structures were characterized by nuclear magnetic resonance. The food accumulation model in mice was established, and the changes of the aqueous extract of S. salsa in gastric emptying and intestinal propulsion rate, colonic tissue lesions, serum brain-gut peptide hormone, colonic tissue protein expression, and gut microbiota structure were compared.

RESULTS

Ten compounds were isolated from S. salsa named as naringenin (1), hesperetin (2), baicalein (3), luteolin (4), isorhamnetin (5), taxifolin (6), isorhamnetin-3-O-β-D-glucoside (7), luteolin-3'-D-glucuronide (8), luteolin-7-O-β-D-glucuronide (9), and quercetin-3-O-β-D-glucuronide (10), respectively. The aqueous extract of S. salsa can improve the pathological changes of the mice colon and intestinal peristalsis by increasing the rate of gastric emptying and intestinal propulsion. By adjusting the levels of 5-HT, CCK, NT, SS, VIP, GT-17, CHE, MTL, and ghrelin, it can upregulate the levels of c-kit, SCF, and GHRL protein, and restore the imbalanced structure of gut microbiota, further achieve the purpose of treating the syndrome of indigestion. The effect is better with the increase of dose.

CONCLUSION

S. salsa has a certain therapeutic effect on mice with the syndrome of indigestion. From the perspective of "brain-gut-gut microbiota", the mechanism of digestion and accumulation of S. salsa was discussed for the first time, which provided an experimental basis for further exploring the material basis of S. salsa.

Relative Frequency of Gastrointestinal Functional Disorders in Patients with Inflammatory Bowel Disease Based on Rome IV: A Case-Control Study

Background

Inflammatory bowel disease (IBD) is a digestive system ailment that causes significant bodily disruption. This problem may coexist with other digestive system illnesses. One of the diseases that reduces the quality of life and other disorders is functional dyspepsia (FD), the diagnosis of which is associated with unique limitations. In this study, we aim to investigate the relative frequency of FD in IBD patients and compare it with a healthy control group.

Materials and Methods

In a case-control study, we selected a group of IBD patients and healthy controls, and all participants were prepared for a diagnosis of FD symptoms using ROME IV criteria. Data were analyzed and compared using Chi-square and t-test, and P ≤ 0.05 was considered significant.

Results

There were 100 IBD patients, including 91 with ulcerative colitis and 9 with Crohn's disease (mean age, 41.37 ± 13; 39 males, 61 females). Furthermore, 100 healthy control subjects (mean age, 44.23 ± 14; 38 males, 62 females) were analyzed. 10% of IBD patients met the criteria of FD, which was comparable with the controls (5, 5%) (P > 0.05). Some of the symptoms of irritable bowel syndrome (IBS) including abdominal pain (P = 0.01) and bowel movement (P = 0.02) were significantly higher in IBD patients than in non-IBD subjects.

Conclusions

The symptoms of FD were not significantly greater in IBD patients compared to the control group, while IBS symptoms were significantly higher in IBD individuals, indicating a possible overlap of Rome IV IBS and FD.

The probiotic fermented milk of Lacticaseibacillus paracasei JY062 and Lactobacillus gasseri JM1 alleviates constipation via improving gastrointestinal motility and gut microbiota

Constipation is directly related to the intestinal microenvironment, in which the promotion of gastrointestinal (GI) motility and improvement of gut microbiota distribution are important for alleviating symptoms. Herein, after the intervention of probiotic fermented milk (FMMIX) containing Lacticaseibacillus paracasei JY062 and Lactobacillus gasseri JM1 for 14 d in Kunming mice with loperamide-induced constipation, the results indicated that FMMIX significantly increased the secretion of serum motilin, gastrin and 5-hydroxytryptamine, as well as decreased the secretion of peptide YY, vasoactive intestinal peptide, and nitric oxide in mice. As determined by immunohistochemical analysis, FMMIX promoted an augmentation in the quantity of Cajal interstitial cells. In addition, the mRNA and protein expression of c-kit and stem cell factor (SCF) were upregulated to facilitate intestinal motility. High-throughput sequencing and gas chromatography techniques revealed that FMMIX led to an increase in the relative abundance of beneficial bacteria (Lactobacillus, Oscillospira, Ruminococcus, Coprococcus, and Akkermansia), reduced the presence of harmful bacteria (Prevotella), and resulted in elevated levels of short-chain fatty acids (SCFA) with a superior improvement compared with unfermented milk. Untargeted metabolomics revealed significant upregulation of functional metabolites such as l-pipecolinic acid, dl-phenylalanine, and naringenin in FMMIX, presumably playing a potential role in constipation relief. Overall, our results showed that FMMIX had the potential to alleviate constipation symptoms in mice by improving the secretion of serum GI regulatory peptides and neurotransmitters, increasing the expression of c-kit and SCF proteins, and modulating the gut microbiota structure and SCFA levels, and may be associated with an increase in these functional metabolites. This suggested that FMMIX could be a promising adjunctive strategy for managing constipation symptoms and could contribute to the development of functional foods aimed at improving gut health.

Effect of Chaihu-Shugan-San on functional dyspepsia and gut microbiota: A randomized, double-blind, placebo-controlled trial

ETHNOPHARMACOLOGICAL RELEVANCE

Chaihu-Shugan-San (CSS) is a classic traditional Chinese medicine (TCM) formula from the Ming Dynasty "Jingyue's Complete Works". In China, it is prevalent for the treatment of a wide range of ailments, with a particular emphasis on functional gastrointestinal disorders (FGIDs). Clinical evidence suggests that CSS has been found to be a highly effective therapeutic approach for the treatment of Functional Dyspepsia (FD), however, there is a limited amount of high-quality clinical evidence, particularly randomized, double-blind, placebo-controlled trials to support this claim.

AIM OF THE STUDY

To evaluate the therapeutic efficacy of Chaihu-Shugan-San (CSS) for treating functional dyspepsia (FD) by comparing it to placebos, as well as to investigate the impact of CSS on the gut microbiota in individuals diagnosed with FD.

MATERIALS AND METHODS

This was a randomized double-blind, placebo-controlled clinical trial implemented at Shuguang Hospital in Shanghai. Between May 2021 and December 2022, 94 participants satisfying the Rome IV diagnostic criteria for FD were enrolled. They were assigned randomly to either the CSS group or the placebo group, with an equal allocation ratio of 1:1. Patients in both groups received the intervention for four weeks. The primary outcome was the dyspepsia symptom scores evaluated by using single dyspepsia symptom scale (SDS) after four weeks of treatment. The secondary outcomes were the solid gastric empties rate measured by a barium strip method, Hamilton anxiety scale (HAMA), Hamilton depression scale (HAMD), and Functional dyspepsia Quality of life scale (FDDQL). In addition, after unblinding, 30 patients in the CSS group were randomly selected and divided into before and after treatment of the FD groups (FD1, FD2), and 30 healthy participants were selected as healthy control group (HC), and the gut microbiota was analyzed by 16S rRNA sequencing.

RESULTS

After four weeks of treatment, the SDS score exhibited a significant improvement in the CSS group compared to the placebo group (t = 4.882; P ＜0.001). The difference in barium strip gastric emptying rate in the CSS group showed a significant ascent compared to the control group (P < 0.01). The HAMA, HAMD, and FDDQL scores in the CSS group showed a statistically significant increase compared to the control group (all P < 0.01). The results of 16S rRNA sequencing revealed that FD patients had less diverse and abundant microbiota than the healthy people. Additionally, the application of CSS resulted in the modulation of certain bacterial populations, leading to both up-regulation and down-regulation of their quantities.

CONCLUSIONS

These findings suggested that CSS is more effective compared to a placebo in treating FD, relieves anxiety and depression, increases gastric emptying rate in FD patients, and that CSS also affects the bacterial community structure in FD patients.

TRIAL REGISTRATION

ChiCTR, ChiCTR2100045793. Registered 25 Mach 2021.

Unraveling the complexity of Disorders of the Gut-Brain Interaction: the gut microbiota connection in children

"Disorders of Gut-Brain Interaction (DGBIs)," formerly referred to as "Functional Gastrointestinal Disorders (FGIDs)," encompass a prevalent array of chronic or recurring gastrointestinal symptoms that notably impact the quality of life for affected children and their families. Recent studies have elucidated the intricate pathophysiology of DGBIs, underscoring their correlation with gut microbiota. This review seeks to explore the present comprehension of the gut microbiota's role in DGBI development. While other factors can contribute to DGBIs, the gut microbiota prominently influences the onset and progression of these conditions. According to the Rome IV diagnostic criteria, DGBI prevalence is approximately 40% worldwide. The Rome Foundation has diligently worked for nearly three decades to refine our comprehension of DGBIs. By centering on the gut microbiota, this review sheds light on potential therapeutic interventions for DGBIs, potentially enhancing the quality of life for pediatric patients and their families.

Improvement of dyspeptic symptoms after Helicobacter pylori eradication therapy in Japanese patients

BACKGROUND AND AIM

Helicobacter pylori eradication therapy effectively improves the abdominal symptoms and bowel habits of patients. Patients in whom dyspepsia is under control by 6 to 12 months after successful H. pylori eradication are defined as having H. pylori-associated dyspepsia, and patients with dyspepsia that is refractory to successful eradication are defined as having functional dyspepsia. Here, we aimed to investigate the association between H. pylori eradication and improvement of dyspepsia in the short and long term after eradication therapy.

METHODS

Dyspeptic symptoms before treatment and at 2 and 12 months after eradication were evaluated using the Gastrointestinal Symptom Rating Scale (GSRS) in 282 H. pylori-positive Japanese patients who underwent eradication therapy.

RESULTS

Of the Japanese H. pylori-positive patients, 48.2% (136/282) had upper abdominal symptoms. Eradication improved dyspepsia in 34.5% (47/136) of the patients at 2 months post eradication, which continued to be under control up to 12 months. A significant decrease at 2 and 12 months after eradication, compared with before eradication, was observed in total GSRS (from 25.7 ± 10.4 [before eradication, n = 249] to 23.3 ± 7.2 [after 2 months, n = 249] and 24.8 ± 7.8 [after 12 months, n = 81]; P = 0.014 and 0.321, respectively), gastric pain score (from 4.1 ± 1.9 to 3.7 ± 1.3 and 3.7 ± 1.2; P = 0.025 and 0.047), and constipation score (from 5.9 ± 3.1 to 5.2 ± 2.3 and 5.9 ± 3.0; P < 0.021 and 0.862).

CONCLUSION

H. pylori-positive dyspepsia patients should be recommended to undergo H. pylori eradication to alleviate dyspepsia-associated symptoms.

Lactobacillus reuteri in digestive system diseases: focus on clinical trials and mechanisms

Objectives

Digestive system diseases have evolved into a growing global burden without sufficient therapeutic measures. Lactobacillus reuteri (L. reuteri) is considered as a new potential economical therapy for its probiotic effects in the gastrointestinal system. We have provided an overview of the researches supporting various L. reuteri strains' application in treating common digestive system diseases, including infantile colic, diarrhea, constipation, functional abdominal pain, Helicobacter pylori infection, inflammatory bowel disease, diverticulitis, colorectal cancer and liver diseases.

Methods

The summarized literature in this review was derived from databases including PubMed, Web of Science, and Google Scholar.

Results

The therapeutic effects of L. reuteri in digestive system diseases may depend on various direct and indirect mechanisms, including metabolite production as well as modulation of the intestinal microbiome, preservation of the gut barrier function, and regulation of the host immune system. These actions are largely strain-specific and depend on the activation or inhibition of various certain signal pathways. It is well evidenced that L. reuteri can be effective both as a prophylactic measure and as a preferred therapy for infantile colic, and it can also be recommended as an adjuvant strategy to diarrhea, constipation, Helicobacter pylori infection in therapeutic settings. While preclinical studies have shown the probiotic potential of L. reuteri in the management of functional abdominal pain, inflammatory bowel disease, diverticulitis, colorectal cancer and liver diseases, its application in these disease settings still needs further study.

Conclusion

This review focuses on the probiotic effects of L. reuteri on gut homeostasis via certain signaling pathways, and emphasizes the importance of these probiotics as a prospective treatment against several digestive system diseases.

The regulatory effects of fucoidan and laminarin on functional dyspepsia mice induced by loperamide

Gastrointestinal dysmotility is a common cause of functional dyspepsia. As two kinds of polysaccharides derived from brown algae, fucoidan and laminarin possess many physiological properties; however, their relative abilities in regulating gastrointestinal motility have not been illustrated yet. In this study, we aimed to investigate the regulatory effect of fucoidan and laminarin on functional dyspepsia mice induced by loperamide. Mice with gastrointestinal dysmotility were treated with fucoidan (100 and 200 mg per kg bw) and laminarin (50 and 100 mg per kg bw). As a result, fucoidan and laminarin reversed the dysfunction mainly through regulating gastrointestinal hormones (motilin and ghrelin), the cholinergic pathway, the total bile acid level, c-kit protein expression, and gastric smooth muscle contraction-related gene expression (ANO1 and RYR3). Moreover, fucoidan and laminarin intervention modulated the gut microbiota profile including the altered richness of Muribaculaceae, Lachnospiraceae, and Streptococcus. The results indicated that fucoidan and laminarin may restore the rhythm of the migrating motor complex and regulate gut microecology. In conclusion, we provided evidence to support that fucoidan and laminarin might have potential abilities to regulate gastrointestinal motility.

Gut Microbiome-Brain Alliance: A Landscape View into Mental and Gastrointestinal Health and Disorders

Gut microbiota includes a vast collection of microorganisms residing within the gastrointestinal tract. It is broadly recognized that the gut and brain are in constant bidirectional communication, of which gut microbiota and its metabolic production are a major component, and form the so-called gut microbiome-brain axis. Disturbances of microbiota homeostasis caused by imbalance in their functional composition and metabolic activities, known as dysbiosis, cause dysregulation of these pathways and trigger changes in the blood-brain barrier permeability, thereby causing pathological malfunctions, including neurological and functional gastrointestinal disorders. In turn, the brain can affect the structure and function of gut microbiota through the autonomic nervous system by regulating gut motility, intestinal transit and secretion, and gut permeability. Here, we examine data from the CAS Content Collection, the largest collection of published scientific information, and analyze the publication landscape of recent research. We review the advances in knowledge related to the human gut microbiome, its complexity and functionality, its communication with the central nervous system, and the effect of the gut microbiome-brain axis on mental and gut health. We discuss correlations between gut microbiota composition and various diseases, specifically gastrointestinal and mental disorders. We also explore gut microbiota metabolites with regard to their impact on the brain and gut function and associated diseases. Finally, we assess clinical applications of gut-microbiota-related substances and metabolites with their development pipelines. We hope this review can serve as a useful resource in understanding the current knowledge on this emerging field in an effort to further solving of the remaining challenges and fulfilling its potential.

Understanding neuroimmune interactions in disorders of gut-brain interaction: from functional to immune-mediated disorders

Functional gastrointestinal disorders-recently renamed into disorders of gut-brain interaction-such as irritable bowel syndrome and functional dyspepsia are highly prevalent conditions with bothersome abdominal symptoms in the absence of structural abnormalities. While traditionally considered as motility disorders or even psychosomatic conditions, our understanding of the pathophysiology has evolved significantly over the last two decades. Initial observations of subtle mucosal infiltration with immune cells, especially mast cells and eosinophils, are since recently being backed up by mechanistic evidence demonstrating increased release of nociceptive mediators by immune cells and the intestinal epithelium. These mediators can activate sensitised neurons leading to visceral hypersensitivity with bothersome symptoms. The interaction between immune activation and an impaired barrier function of the gut is most likely a bidirectional one with alterations in the microbiota, psychological stress and food components as upstream players in the pathophysiology. Only few immune-targeting treatments are currently available, but an improved understanding through a multidisciplinary scientific approach will hopefully identify novel, more precise treatment targets with ultimately better outcomes.

Gastrointestinal symptoms, gut microbiome, probiotics and prebiotics in anorexia nervosa: A review of mechanistic rationale and clinical evidence

Recent research has revealed the pivotal role that the gut microbiota might play in psychiatric disorders. In anorexia nervosa (AN), the gut microbiota may be involved in pathophysiology as well as in the gastrointestinal (GI) symptoms commonly experienced. This review collates evidence for the potential role of gut microbiota in AN, including modulation of the immune system, the gut-brain axis and GI function. We examined studies comparing gut microbiota in AN with healthy controls as well as those looking at modifications in gut microbiota with nutritional treatment. Changes in energy intake and nutritional composition influence gut microbiota and may play a role in the evolution of the gut microbial picture in AN. Additionally, some evidence indicates that pre-morbid gut microbiota may influence risk of developing AN. There appear to be similarities in gut microbial composition, mechanisms of interaction and GI symptoms experienced in AN and other GI disorders such as inflammatory bowel disease and functional GI disorders. Probiotics and prebiotics have been studied in these disorders showing therapeutic effects of probiotics in some cases. Additionally, some evidence exists for the therapeutic benefits of probiotics in depression and anxiety, commonly seen as co-morbidities in AN. Moreover, preliminary evidence for the use of probiotics in AN has shown positive effects on immune modulation. Based on these findings, we discuss the potential therapeutic role for probiotics in ameliorating symptoms in AN.

Effects of Plant-Derived Glycerol Monolaurate (GML) Additive on the Antioxidant Capacity, Anti-Inflammatory Ability, Muscle Nutritional Value, and Intestinal Flora of Hybrid Grouper (Epinephelus fuscoguttatus♀ × Epinephelus lanceolatus♂)

In a context where the search for plant-derived additives is a hot topic, glycerol monolaurate (GML) was chosen as our subject to study its effect on grouper (Epinephelus fuscoguttatus♀ × Epinephelus lanceolatus♂). Seven gradient levels of GML (0, 600, 1200, 1800, 2400, 3000, and 3600 mg/kg) were used for the experiment. Based on our experiments, 1800 mg/kg GML significantly increased the final body weight (FBW) and weight gain rate (WGR). GML increased the activity of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) and decreased malondialdehyde (MDA). Adding 1800 mg/kg GML also significantly increased the levels of lauric acid (C12:0) (LA), n-3 polyunsaturated fatty acids (PFA), and the n-6 PFA-to-n-3/n-6 ratio, while significantly decreasing the levels of saturated fatty acids (SFA). Dietary supplementation with GML significantly inhibited the expression of pro-inflammatory factors and reduced the occurrence of inflammation. GML improved intestinal flora and the abundance of beneficial bacteria (Bacillus, Psychrobacter, Acinetobacter, Acinetobacter, Stenotrophomonas, and Glutamicibacter). It provides a theoretical basis for the application of GML in aquafeed and greatly enhances the possibility of using GML in aquafeed. Based on the above experimental results, the optimum level of GML in grouper feed is 1800 mg/kg.