Gut Health in the era of the human gut microbiota: from metaphor to biovalue

Older adults and healthcare professionals have limited awareness of the link between the Mediterranean diet and the gut microbiome for healthy aging

Objectives

Strategies to improve the gut microbiome through consuming an improved diet, including adopting the Mediterranean Diet (MD), may promote healthy aging. We explored older adults' and healthcare professionals' (HCPs) perspectives of the MD, gut health, and microbiome for their role in healthy aging.

Design

Phenomenological qualitative.

Setting

Community-dwelling older adults and HCPs in primary and secondary care in Ireland.

Participants

Older adults (aged 55 + years), recruited through social, retirement and disease-support groups. HCPs recruited through researcher networks and professional associations.

Measurements

Semi-structured 1:1 interviews and focus groups (FGs) conducted remotely with older adults and HCPs separately. Interviews/FGs were recorded, transcribed, and coded using inductive thematic analysis.

Results

Forty-seven older adults were recruited (50% male; 49% aged 60-69 years; 28% 70 +), and 26 HCPs including dietitians (n = 8); geriatricians (n = 6); clinical therapists (n = 4); nurses, pharmacists, catering managers, and meal-delivery service coordinators (n = 2 each). Older adults considered the MD "a nice way to enjoy food," good for cardiovascular health and longevity, but with accessibility and acceptability challenges (increased salads/fish, different food environments, socio-cultural differences). HCPs felt the MD is included in healthy eating advice, but not overtly, mostly through the promotion of mixed-fiber intake. Older adults considered "live" yogurt and probiotics, and to a lesser extent fiber, to maintain a "healthy gut," suggesting the gut has "something to do with" cognitive and digestive health. Overall, microbiota-health effects were considered "not common knowledge" among most older adults, but becoming more topical among both professionals and the public with advancing scientific communication.

Conclusion

While "gut health" was considered important, specific effects of the MD on gut microbiota, and the significance of this for healthy aging, was under-recognized. Future efforts should explain the importance to older adults of maintaining the gut microbiota through diet, while appreciating perspectives of probiotic products and supplements.

Environmentality in biomedicine: microbiome research and the perspectival body

Microbiome research shows that human health is foundationally intertwined with the ecology of microbial communities living on and in our bodies. This challenges the categorical separation of organisms from environments that has been central to biomedicine, and questions the boundaries between them. Biomedicine is left with an empirical problem: how to understand causal pathways between host health, microbiota and environment? We propose a conceptual tool - environmentality - to think through this problem. Environmentality is the state or quality of being an environment for something else in a particular context: a fully perspectival proposition. Its power lies partly in what Isabelle Stengers has called the efficacy of the word itself, contrasting the dominant sense of the word environment as something both external and fixed. Through three case studies, we argue that environmentality can help think about the causality of microbiota vis-a-vis host health in a processual, relational and situated manner, across scales and temporalities. We situate this intervention within historical trajectories of thought in biomedicine, focusing on the challenge microbiome research poses to an aperspectival body. We argue that addressing entanglements between microbial and human lives requires that the environment is brought into the clinic, thus shortening the conceptual gap between medicine and public health.

<i>Helicobacter pylori</i>. The survival strategy of a commensal symbiont in the <i>Homo sapiens</i> population

Несмотря на крайне высокую степень инфицированности Helicobacter pylori в популяции Homo sapiens, подавляющее большинство инфицированных являются бессимптомными носителями. Широкое распространение инфекции H. pylori среди лиц без признаков патологии и низкая заболеваемость при хронической колонизации слизистой оболочки желудка указывают на то, что H. pylori с большей вероятностью является условно-патогенным микроорганизмом или патобионтом. Популяционная ликвидация инфекции H. pylori существенно снизила заболеваемость инфекцией H. pylori, однако появление устойчивости к противомикробным препаратам привело к их неэффективности.