Gut Microbiota, Diet and Health. (We and our gut microbes)

Pomegranate fruit pulp polyphenols reduce diet-induced obesity with modulation of gut microbiota in mice

BACKGROUND

Pomegranate is a rich source of polyphenols and has been used as a dietary supplement and pharmaceutical ingredient. This study aimed to investigate the pomegranate fruit pulp polyphenols (PFP) with regard to their anti-obesity activity and gut microbiota-modulating effect in mice. Thirty-six 4-week-old specific pathogen-free C57BL/6J mice (weight: 17.7-20.8 g) were randomly divided into three groups and fed with low-fat diet (10% fat energy), high-fat diet (HFD) (45% fat energy), or HFD supplemented with PFP by intragastric administration for 14 weeks. The obesity-related clinical indicators were investigated, and the composition of fecal microbiota was analyzed by 16S rRNA sequencing.

RESULTS

Our results showed that PFP treatment reduced HFD-induced body weight gain by 35.23% (P < 0.05), steatosis scores by 50% (P < 0.05) and insulin resistance by 56.84% (P < 0.05), compared with the mice fed HFD alone. Moreover, compared with the mice in the HFD group, PFP supplement changed the composition of the gut microbiota, and enriched Akkermansia muciniphila, Parabacteroides distasonis, Bacteroides acidifaciens, Mucispirillum schaedleri and Lachnospiraceae bacterium 28-4, which were negatively correlated with physical biomarkers, including body weight, glucose, triglycerides and total cholesterol.

CONCLUSION

PFP alleviated HFD-induced obesity, insulin resistance and hepatic steatosis in mice, and the changes in the gut microbiota might be one of the potential mechanisms through which PFP improved obesity and obesity-related disorders, eventually benefiting the recipient. © 2021 Society of Chemical Industry.

Correlation between Gut Microbiota and Six Facets of Neuroticism in Korean Adults

A person high in neuroticism is more likely to experience anxiety, stress, worry, fear, anger, and depression. Previous studies have shown that the gut microbiota can influence personality and mental disorders, including stress, anxiety, and depression, through the gut-brain axis. Here, we investigated the correlations between the sub-facet of neuroticism and gut microbiota using the Revised NEO Personality Inventory and the 16S rRNA gene sequencing data 784 adults. We found that the high anxiety and vulnerability group showed significantly lower richness in microbial diversity than a group with low anxiety and vulnerability. In beta diversity, there was a significant difference between the low and high groups of anxiety, self-consciousness, impulsiveness, and vulnerability. In taxonomic compositions, Haemophilus belonging to Gammaproteobacteria was correlated with the Neuroticism domain as well as N1 anxiety and N6 vulnerability facets. The high N1 anxiety and N6 vulnerability group was correlated with a low abundance of Christensenellaceae belonging to Firmicutes Clostridia. High N4 self-consciousness was correlated with a low abundance of Alistipes and Sudoligranulum. N5 impulsiveness was correlated with a low abundance of Oscillospirales. Our findings will contribute to uncovering the potential link between the gut microbiota and neuroticism, and the elucidation of the correlations of the microbiome-gut-brain axis with behavioral changes and psychiatric cases in the general population.

Identifying Potential Polymicrobial Pathogens: Moving Beyond Differential Abundance to Driver Taxa

It is now recognized that some diseases of aquatic animals are attributed to polymicrobial pathogens infection. Thus, the traditional view of "one pathogen, one disease" might mislead the identification of multiple pathogens, which in turn impedes the design of probiotics. To address this gap, we explored polymicrobial pathogens based on the origin and timing of increased abundance over shrimp white feces syndrome (WFS) progression. OTU70848 Vibrio fluvialis, OTU35090 V. coralliilyticus, and OTU28721 V. tubiashii were identified as the primary colonizers, whose abundances increased only in individuals that eventually showed disease signs but were stable in healthy subjects over the same timeframe. Notably, the random Forest model revealed that the profiles of the three primary colonizers contributed an overall 91.4% of diagnosing accuracy of shrimp health status. Additionally, NetShift analysis quantified that the three primary colonizers were important "drivers" in the gut microbiotas from healthy to WFS shrimp. For these reasons, the primary colonizers were potential pathogens that contributed to the exacerbation of WFS. By this logic, we further identified a few "drivers" commensals in healthy individuals, such as OUT50531 Demequina sediminicola and OTU_74495 Ruegeria lacuscaerulensis, which directly antagonized the three primary colonizers. The predicted functional pathways involved in energy metabolism, genetic information processing, terpenoids and polyketides metabolism, lipid and amino acid metabolism significantly decreased in diseased shrimp compared with those in healthy cohorts, in concordant with the knowledge that the attenuations of these functional pathways increase shrimp sensitivity to pathogen infection. Collectively, we provide an ecological framework for inferring polymicrobial pathogens and designing antagonized probiotics by quantifying their changed "driver" feature that intimately links shrimp WFS progression. This approach might generalize to the exploring disease etiology for other aquatic animals.

Association between fecal microbiota and generalized anxiety disorder: Severity and early treatment response

BACKGROUND

Associations between abnormal gut microbiome compositions and anxiety-like behaviors are well established. However, it is unknown whether the gut microbiome composition is associated with the severity of generalized anxiety disorder (GAD) and relief from clinical symptoms in patients.

METHODS

Stool samples from 36 patients with active GAD (A-GAD group) and 24 matched healthy control subjects (HC group) were analyzed by 16S rRNA gene sequencing. Anxiety was assessed with the Hamilton Anxiety Rating Scale and the Self-rating Anxiety Scale, and global assessments of functioning were performed at baseline and 1 month after drug treatment.

RESULTS

Gut microbiome compositions were altered in A-GAD patients, with fewer operational taxonomic units and lower fecal bacterial α-diversity. Specifically, Firmicutes and Tenericutes abundances were lower in A-GAD patients, and several genera were differentially represented in the A-GAD and HC groups. The abundances of Eubacterium_coprostanoligenes_group, Ruminococcaceae_UCG-014, and Prevotella_9 correlated negatively with the anxiety severity and positively with anxiety reduction, whereas the abundances of Bacteroides and Escherichia-Shigella were positively associated with anxiety severity. Sex, smoking, and alcohol intake influenced the gut microbiome composition.

LIMITATIONS

The sample sizes were small and the stool samples were collected only at baseline; therefore, a causal association between changes in intestinal flora and disease remission was not established. Moreover, the effects of different drugs on gut microbiome composition were not investigated.

CONCLUSIONS

Altered gut microbiome composition may contribute to GAD pathogenesis and remission.

Characterization and Comparison of Microbiota in the Gastrointestinal Tracts of the Goat (Capra hircus) During Preweaning Development

Bacterial communities in gastrointestinal tracts (GIT) play an important role in animal health and performance. Despite its importance, little information is available on the establishment of microbial populations in the goat GIT or on changes occurring during early development. Therefore, this study investigated the bacterial community dynamics of the rumen, duodenum, jejunum, ileum, cecum, and colon in 15 goats at five developmental stages (0, 14, 28, 42, and 56 days old) by using 16S rDNA sequencing and quantitative real-time PCR technology. 940 genera were found to belong to 44 phyla distributed along the GIT. As a whole, the microbial richness and diversity showed a clear increasing trend as the kids aged and alpha diversity differed significantly among GIT compartments mainly occurring at middle day ages (14 and 28 days). Principal coordinate analysis indicated that the bacterial community displayed distinct temporal and spatial specificity along the GIT in preweaning goats. As kids aged, the phylum Firmicutes was replaced by Bacteroidetes in rumen, whereas Proteobacteria in the large intestine was displaced by Firmicutes. The phylum Proteobacteria was mainly present in the small intestine in older animals. In the rumen, taxa, such as Bacillus and Lactococcus decreased and Prevotella, Treponema, Ruminococcus, and unclassified Prevotellaceae increased with the age of kids. Furthermore, a lower proportion of taxa, such as Lactobacillus and Bacteroides was observed with higher abundances of both Christensenellaceae_R_7 and Ruminococcus in duodenum and jejunum in older animals. In the large intestine, the microbiota displayed taxonomic dynamics with increases of Ruminococcaceae UCG 005, unclassified Lachnospiraceae, Barnesiella, and Blautia as kids aged. Predicted pathway analysis suggested that genes involved in amino acid metabolism, and translation were abundant in both rumen and duodenum, while genes involved in membrane transport and carbohydrate metabolism were enriched in the large intestine. These results indicate that both the microbial colonization process and potential function exert a temporal-spatial specificity throughout the GIT of goats. This study provides new insight into the temporal dynamics of GIT microbiota development during preweaning and will aid to develop strategies for improving animal health and downstream production.

Influence of Bactrian camel milk on the gut microbiota

Bactrian camel milk has become popular in the market as an important source of nutrients with diverse functional effects. In this study, the influence of Bactrian camel milk on the gut microbiota of mice was studied using metagenomic-based sequencing of the V3 and V4 hypervariable regions of the 16S rRNA gene. Bioinformatics analysis showed that Firmicutes and Bacteroidetes were the predominant phyla, accounting for more than 80% of the bacteria present. At the genus level, Allobaculum, Akkermansia, Romboutsia, Bifidobacterium, and Lactobacillus were most abundant in the gut microbiota; of these, Allobaculum and Akkermansia were the predominant genera, representing 40.42 and 7.85% of all the bacteria present, respectively. Camel milk was found to reduce relative abundance of Romboutsia, Lactobacillus, Turicibacter, and Desulfovibrio (decreased by 50.88, 34.78, 26.67, and 54.55%, respectively) in the gut microbiota compared with the control. However, some genera such as Allobaculum, Akkermansia, and Bifidobacterium in the gastrointestinal flora increased in abundance in the presence of camel milk; these genera are correlated with beneficial effects for organisms. Our research suggests that the gut microbiota should be taken into account when conducting functional studies on camel milk, and this work provides a useful foundation for further study on functions of camel milk.