The association between gut microbiota and resting metabolic rate in overweight/obese women: a case-control study

Plant-based dietary indices association with appetite, appetite regulating peptides and gut microbiota in healthy women: a cross-sectional study

PURPOSE

Plant-based diets are associated with improved appetite regulation. Moreover, gut microbiota has been linked to appetite. The present study aims to determine the association between plant-based dietary indices (PDIs) and appetite-regulating peptides (fasting level of Leptin, GLP-1, and ghrelin) and gut microbiota profile in healthy women. Furthermore, the potential covariate role of gut microbiota in the association between PDIs and appetite is investigated.

METHODS

This cross-sectional study was conducted on 91 healthy women (18-50 years). Body composition, anthropometric indices, dietary intake, PDIs, subjective appetite, appetite-regulating peptides (fasting level of leptin, GLP-1, and ghrelin), physical activity, sleep quality, and gut microbiota profile were evaluated.

RESULTS

There was a significant inverse association between scores of PDI and healthful plant-based dietary index (hPDI) with leptin and IL-6 (p < 0.05). A higher hPDI was associated with a lower GLP-1 concentration (p = 0.04). Additionally, uPDI (unhealthful plant-based diet index) was inversely associated with satiety (p = 0.02) and positively associated with hunger (p = 0.02). Moreover, higher PDI was associated with higher Prevotella abundance (p = 0.01). Our findings suggest that Firmicutes and the Firmicutes/Bacteroidetes ratio might be involved in the associations between hPDI and both leptin and GLP-1 levels. Additionally, A. muciniphila may play a role in the association between hPDI and GLP-1 levels as a relevant microbial factor. However, the potential mediating effects of these bacteria should be investigated in future studies.

CONCLUSION

We indicated an inverse association between higher PDI and hPDI scores with appetite-related hormones and IL-6. Moreover, higher uPDI was related to appetite sensation and a higher PDI score increased the abundance of Prevotella. The association between hPDI scores and appetite-regulating hormones may be influenced by the gut microbiota. Considering lower levels of fasting GLP-1 in relation with hPDI, it appears further evaluation of the postprandial state of GLP-1 in cohort studies or intervention trials is also warrented to better elucidate their association.

Individual Difference in the Capacity of Gut Microbiota to Ferment Four Complex Carbohydrates from Normal to Overweight People: An In Vitro Study

Pectic polysaccharides can beneficially shape the human microbiota. However, individual variability in the microbial response, especially the response between normal-weight (NW) and overweight (OW) people, is rarely understood. Therefore, we performed batch fermentation using inulin (INU), commercial pectin (CP), and pectic polysaccharides extracted from goji berry (GPP) and raspberry (RPP) by microbiota from five normal-weight (NW) and five overweight (OW) donors. The degree of specificity of fiber was negatively correlated to its fermentable rate and microbial response. Meanwhile, we found that microbiota from OW donors had a stronger fiber-degrading capacity than NW donors. The result of correlation between individual basal microbiota and the fermentable rate indicated Dialister, Megamonas, Oscillospiraceae_NK4A214, Prevotella, Ruminococcus, and unidentified_Muribaculaceae may be the key bacteria. In summary, we highlighted a new perspective regarding the interactive relationship between different fibers and fecal microbiota from different donors that may be helpful to design fiber interventions for individuals with different microbiota.

Gut microbial genomes with paired isolates from China illustrate probiotic and cardiometabolic effects

The gut microbiome displays genetic differences among populations, and characterization of the genomic landscape of the gut microbiome in China remains limited. Here, we present the Chinese Gut Microbial Reference (CGMR) set, comprising 101,060 high-quality metagenomic assembled genomes (MAGs) of 3,707 nonredundant species from 3,234 fecal samples across primarily rural Chinese locations, 1,376 live isolates mainly from lactic acid bacteria, and 987 novel species relative to worldwide databases. We observed region-specific coexisting MAGs and MAGs with probiotic and cardiometabolic functionalities. Preliminary mouse experiments suggest a probiotic effect of two Faecalibacillus intestinalis isolates in alleviating constipation, cardiometabolic influences of three Bacteroides fragilis_A isolates in obesity, and isolates from the genera Parabacteroides and Lactobacillus in host lipid metabolism. Our study expands the current microbial genomes with paired isolates and demonstrates potential host effects, contributing to the mechanistic understanding of host-microbe interactions.