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.