The Influence of the Western Diet on Microbiota and Gastrointestinal Immunity

Diet exerts a major influence upon host immune function and the gastrointestinal microbiota. Although components of the human diet (including carbohydrates, fats, and proteins) are essential sources of nutrition for the host, they also influence immune function directly through interaction with innate and cell-mediated immune regulatory mechanisms. Regulation of the microbiota community structure also provides a mechanism by which food components influence host immune regulatory processes. Here, we consider the complex interplay between components of the modern (Western) diet, the microbiota, and host immunity in the context of obesity and metabolic disease, inflammatory bowel disease, and infection. Expected final online publication date for the Annual Review of Food Science and Technology, Volume 13 is March 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Dietary Supplementation with Goji Berries (Lycium barbarum) Modulates the Microbiota of Digestive Tract and Caecal Metabolites in Rabbits

Goji berries show health benefits, although the possible mechanisms of action, including compositional changes in the gut microbiome, are still not fully understood. The aim of this study was to evaluate the effect of Goji berry supplementation on microbiota composition and metabolites in the digestive tracts of rabbits. Twenty-eight New Zealand White rabbits were fed with a commercial feed (control group, C; n = 14) or the same diet supplemented with 3% of Goji berries (Goji group, G; n = 14), from weaning (35 days old) until slaughter (90 days old). At slaughter, samples from the content of the gastrointestinal tracts were collected and analyzed by Next Generation 16S rRNA Gene Sequencing to evaluate the microbial composition. Ammonia and lactic acid were also quantified in caecum. Results showed differences in microbiota composition between the groups for two phyla (Cyanobacteria and Euryarchaeota), two classes (Methanobacteria and Bacilli), five orders, fourteen families, and forty-five genera. Ruminococcaceae (p < 0.05) and Lachnospiraceae (p < 0.01) were more abundant in G than in C group. Lactobacillaceae also showed differences between the two groups, with Lactobacillus as the predominant genus (p = 0.002). Finally, Goji berry supplementation stimulated lactic acid fermentation (p < 0.05). Thus, Goji berry supplementation could modulate gastrointestinal microbiota composition and caecal fermentation.

Evaluation of the Antibacterial and Prebiotic Potential of Ascophyllum nodosum and Its Extracts Using Selected Bacterial Members of the Pig Gastrointestinal Microbiota

Ascophyllum nodosum and its extracts are promising antibacterial and prebiotic dietary supplements for pigs. The objectives of this study were to evaluate the effects of the increasing concentrations of: (1) two whole biomass samples of A. nodosum with different harvest seasons, February (ANWB-F) and November (ANWB-N), in a weaned pig faecal batch fermentation assay, and (2) A. nodosum extracts produced using four different extraction conditions of a hydrothermal-assisted extraction methodology (ANE1–4) and conventional extraction methods with water (ANWE) and ethanol (ANEE) as solvent in individual pure culture growth assays using a panel of beneficial and pathogenic bacterial strains. In the batch fermentation assay, ANWB-F reduced Bifidobacterium spp. counts (p < 0.05) while ANWB-N increased total bacterial counts and reduced Bifidobacterium spp. and Enterobacteriaceae counts (p < 0.05). Of the ANE1–4, produced from ANWB-F, ANWE and ANEE that were evaluated in the pure culture growth assays, the most interesting extracts were the ANE1 that reduced Salmonella Typhimurium, enterotoxigenic Escherichia coli and B. thermophilum counts and the ANE4 that stimulated B. thermophilum growth (p < 0.05). In conclusion, the extraction method and conditions influenced the bioactivities of the A. nodosum extracts with ANE1 and ANE4 exhibiting distinct antibacterial and prebiotic properties in vitro, respectively, that merit further exploration.

Consumption of supplementary inulin modulates milk microbiota and metabolites in dairy cows with subclinical mastitis

Milk microbiota and mediated metabolites directly affect the health of the udder in dairy cows. Inulin, a dietary prebiotic, can modulate the profile of gastrointestinal microbiota. However, whether the inulin intake affects the milk microbial population and metabolites remains unknown. In this study, forty subclinical mastitis (SCM) cows were randomly divided into 5 groups. Five inulin addition doses, 0, 100, 200, 300 and 400 g/d per cow, based on the same basal diet were supplemented, respectively. The experiments lasted for 8 weeks. The results showed lower relative abundance of mastitic-causing and pro-inflammation microbes in milk (i.e., Escherichia -Shigella , Pseudomonas , Rhodococcus and Burkholderia-Caballeronia-Paraburkholderia , etc.), and higher probiotics and commensal bacteria, such as, Lactobacillus , Bifidobacterium , etc. in the cows fed 300 g/d inulin, compared with the control group. Meanwhile, the levels of arachidonic acid pro-inflammatory mediators (leukotriene E3, 20-carboxy-leukotriene B4 and 12-Oxo-c-LTB3) and phospholipid metabolites were reduced, and the levels of compounds with antibacterial and anti-inflammatory potential (prostaglandin A1 and 8-iso-15-Keto-PGE 2 , etc.), and participating energy metabolism (citric acid and L-Carnitine, etc.) were elevated. These data suggested that inulin intake might modulate the microflora and metabolites level in extra-intestinal tissue, such as mammary gland, which provided an alternative for the regulation and mitigation for SCM. IMPORTANCE The profile of microbial community and metabolic activity in milk are main determinant of udder health status and milk quality. Recent studies have demonstrated that diet could directly modulate mammary gland microbiome. Inulin is a probiotic dietary fiber, which can improve the microbiota population in gastrointestinal tract. However, whether inulin intake can further regulate the profile of microbiota and metabolic activities in milk remains unclear. In subclinical mastitic cows, we found that inulin supplementation could reduce the abundance of Escherichia -Shigella , Pseudomonas , Rhodococcus , Burkholderia-Caballeronia-Paraburkholderia and the levels of (±)12, 13 - DiHOME, leukotriene E3 and 20-Carboxy-Leukotriene B4 etc., while, elevated the abundance of Lactobacillus , Bifidobacterium , and Muribaculaceae as well as the levels of prostaglandin A1 (PGA1), 8-iso-15-keto-PGE2 and benzoic acid etc., in milk. These data suggest that inulin intake affects the profile of microorganisms and metabolites in milk, which provides an alternative for the regulation of mastitis.

Gastrointestinal Microbiota Changes in Patients With Gastric Precancerous Lesions

BackgroundGastric microbiota may be involved in gastric cancer. The relationship between gastrointestinal microbes and the risk of gastric cancer is unclear. This study aimed to explore the gastric and intestinal bacteria associated with gastritis and gastric precancerous lesions. We conducted a case-control study by performing 16S rRNA gene analysis of gastric biopsies, juices, and stool samples from 148 cases with gastritis or gastric precancerous lesions from Anhui and neighboring provinces, China. And we validated our findings in public datasets.ResultsAnalysis of microbial sequences revealed decreased bacterial alpha diversity in gastric bacteria during the progression of gastritis. Helicobacter pylori was the main contributor to the decreased microbial composition and diversity in the gastric mucosa and had little influence on the microbiota of gastric juice and feces. The gastric mucosal genera Gemella, Veillonella, Streptococcus, Actinobacillus, and Hemophilus had the higher degree of centrality across the progression of gastric precancerous lesions. And Acinetobacter may contribute to the occurrence of intraepithelial neoplasia. In addition, the microbial model of H. pylori-positive gastric biopsies and feces showed value in the prediction of gastric precancerous lesions.ConclusionsThis study identified associations between gastric precancerous lesions and gastric microbiota, as well as the changes in intestinal microbiota, and explored their values in the prediction of gastric precancerous lesions.

Gut microbiota composition does not associate with Toxoplasma infection in rats

Toxoplasma infection in intermediate host species closely associates with inflammation. This association has led to suggestions that the behavioural changes associated with infection may be indirectly driven by the resulting sustained inflammation rather than a direct behavioural manipulation by the parasite. If this is correct, sustained inflammation in chronically infected rodents should present as widespread changes in the gastrointestinal microbiota due to the dependency between the composition of these microbiota and sustained inflammation. We conducted a randomized controlled experiment in rats that were assigned to a Toxoplasma-treatment, placebo-treatment or negative control group. We sacrificed rats during the chronic phase of infection, collected their cecal stool samples and sequenced the V3-V4 region of the 16S rRNA gene to characterise the bacterial community in these samples. Toxoplasma infection did not induce widespread changes in the bacterial community composition of the gastrointestinal tract of rats. Rather, we found sex differences in the bacterial community composition and only minor changes in Toxoplasma infected rats. We conclude that it is unlikely that sustained inflammation is the mechanism driving the highly specific behavioural changes observed in Toxoplasma-positive rats.

Gastrointestinal Microbiota and Parasite-Fauna of Wild Dissostichus eleginoides Smitt, 1898 Captured at the South-Central Coast of Chile

Dissotichus eleginoides has a discontinuous circumpolar geographic distribution restricted to mountains and platforms, mainly in Subantarctic and Antarctic waters of the southern hemisphere, including the Southeast Pacific, Atlantic and Indian oceans and in areas surrounding the peninsular platforms of subantarctic islands. The aim of this work was to determine and characterize the gastrointestinal parasitic and microbial fauna of specimens of D. eleginoides captured in waters of the south-central zone of Chile. The magnitude of parasitism in D. eleginoides captured in waters of the south-central zone of Chile is variable, and the parasite richness is different from that reported in specimens from subantarctic environments. Next-generation sequencing (NGS) of the microbial community associated to intestine showed a high diversity, where Proteobacteria, Firmicutes, and Bacteriodetes were the dominant phyla. However, both parasitic and microbial structures can vary between fish from different geographic regions

Differences in the Composition of Gut Microbiota between Patients with Parkinson’s Disease and Healthy Controls: A Cohort Study

Gut microbiome and colonic inflammation can be associated with the predisposition and progression of Parkinson’s disease (PD). The presented study aimed to compare gastrointestinal microbiota composition between patients diagnosed with PD and treated only with Levodopa to healthy controls. In this prospective study, patients were recruited in 1 academic hospital from July 2019 to July 2020. The detailed demographic data and medical history were collected using a set of questionnaires. Fecal samples were obtained from all participants. Next-Generation Sequencing was used to assess the microbiota composition. The endpoint was the difference in composition of the gut microbiota. In this study, we enrolled 27 hospitalized PD patients with well-controlled symptoms. The control group included 44 healthy subjects matched for age. Among PD patients, our results presented a higher abundance of Bacteroides phylum, class Corynebacteria among phylum Actinobacteria, class Deltaproteobacteria among phylum Proteobacteria, and genera such as Butyricimonas, Robinsoniella, and Flavonifractor. The species Akkermansia muciniphila, Eubacterium biforme, and Parabacteroides merdae were identified as more common in the gut microbiota of PD patients. In conclusion, the patients diagnosed with PD have significantly different gut microbiota profiles in comparison with healthy controls.

A Faithful Gut: Core Features of Gastrointestinal Microbiota of Long-Distance Migratory Bats Remain Stable despite Dietary Shifts Driving Differences in Specific Bacterial Taxa

Migratory animals live in a world of constant change. The whole-body ecosystem needs a strong adapting capacity to thrive despite the changes.

SARS-CoV-2 as a Trigger in the Development of Tourette’s-Like Symptoms: A Case Report

Background: Reports have been surfacing surrounding CNS-associated symptoms in individuals affected by coronavirus disease 19 (COVID-19). Tourette syndrome is a neuropsychiatric disorder with usual onset in childhood. Gut microbiota can affect central physiology and function via the microbiota-gut-brain axis. The authors of this case report describe Tourette’s-like symptoms in a patient resulting from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection disrupting gut microbiota. Case Presentation: This case involves a 16-year-old female that developed acute onset Tourette’s-like symptoms along with neuropsychiatric symptoms after exposure to and infection from SARS-CoV-2. The patient had negative nasopharyngeal (NP) real-time reverse transcription-PCR (RT-PCR) tests for SARS-CoV-2 on five occasions from August of 2020 through June of 2021. The patient’s symptoms continued to worsen over the next six months until next-generation sequencing (NGS) revealed SARS-CoV-2 in her stool. Repair of the gastrointestinal microbiota, treatment with nutraceutical and pharmaceutical agents, as well as alterations in her surroundings resulted in dramatic improvement in the microbiome and a significant reduction of symptoms.Discussion: The use of RT-PCR testing to determine the presence or absence of SARS-CoV-2 may be inadequate and inaccurate for individuals that have been exposed to the virus. In addition, the impact of SARS-CoV-2 infection to the GI tract may cause significant havoc in the gut microbiota which may lead to disruption of the blood brain barrier, disruption to the gut- microbiome-brain axis, and neurological symptoms. Additional testing, eradication of infectious agents, as well as restoration of the gut microbiome are needed to effectively manage and treat this condition.