Diet, anthropometric measurements, sleep quality and fecal levels of Akkermansia muciniphila: a cross-sectional study in older adults

Introduction: Akkermansia muciniphila is a mucin-degrading bacterium that has been linked to metabolic and gut-barrier health, yet population-specific data are scarce in Latin America. No Peruvian study has examined how diet and other factors relate to its fecal levels. This study aimed to evaluate the association between dietary intake, anthropometric measurements, sleep quality, and fecal levels of A. muciniphila in a specific population of older Peruvian adults. Methods: In this cross-sectional analytical study, 111 older adults (≥ 60 years) residing in Lima, Peru, were recruited. Absolute A. muciniphila levels (Log₁₀ copies g^-1 stool) were determined by real-time PCR. Dietary intake was assessed with a semi-quantitative food-frequency questionnaire covering 54 foods, grouped into four consumption categories (daily, weekly, monthly, none). Anthropometric measurements, sleep quality (Pittsburgh Sleep Quality Index, PSQI) and sociodemographic variables were also recorded. Group differences were tested with t-tests or one-way ANOVA followed by Tukey’s HSD; effect sizes were expressed as Cohen’s d or ω². Results: A. muciniphila was quantifiable in 69 of the 111 participants (62%), with fecal abundance ranging across four logarithmic units (Log₁₀ 4.3–9.4 copies g-¹). In the analysis restricted to participants positive for the bacterium (69/111), monthly consumption of dried split peas (Pisum sativum) and canary beans (Phaseolus vulgaris) was positively associated with higher A. muciniphila levels (p < 0.05; ω2 = 0.11), whereas weekly consumption or the absence of intake of these foods showed no association. Moreover, no significant associations were observed with body mass index (BMI), waist or calf circumference, sleep quality, medication use, or other sociodemographic variables. Conclusions: In this first Peruvian study linking diet to A. muciniphila, monthly consumption of specific legumes was positively associated with its fecal levels. No associations were observed with anthropometric or sociodemographic factors. These findings highlight the potential dietary influence on beneficial gut microbes in older adults and underscore the need for longitudinal and metagenomic studies across broader Peruvian populations.