Sex, Body Mass Index, and Dietary Fiber Intake Influence the Human Gut Microbiome

Abstract Background A higher intake of dietary fiber is associated with a decreased risk of chronic inflammatory diseases such as cardiovascular disease and inflammatory bowel disease. This may function in part due to abrogation of chronic systemic inflammation induced by factors such as dysbiotic gut communities. Data regarding the detailed influences of long-term and recent intake of differing dietary fiber sources on the human gut microbiome are lacking. Methods In a cohort of 307 generally healthy men, we examined gut microbiomes, profiled by shotgun metagenomic and metatranscriptomic sequencing, and long-term and recent dietary fiber intake in relation to plasma levels of C-reactive protein (CRP), an established biomarker for chronic inflammation. Data were analyzed using multivariate linear mixed models. Results We found that inflammation-associated gut microbial configurations corresponded with higher CRP levels. A greater intake of dietary fiber was associated with shifts in gut microbiome composition, particularly Clostridiales, and their potential for carbohydrate utilization via polysaccharide degradation. This was particularly true for fruit fiber sources (i.e., pectin). Most striking, fiber intake was associated with significantly greater CRP reduction in individuals without substantial Prevotella copri carriage in the gut, whereas those with P. copri carriage maintained stable CRP levels regardless of fiber intake. Conclusions Our findings offer human evidence supporting a fiber-gut microbiota interaction, as well as a potential specific mechanism by which gut-mediated systemic inflammation may be mitigated.

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Association between the Distal Gut Microbiome and Anxiety in Highly Active Individuals

10.21203/rs.3.rs-26541/v1 ◽

2020 ◽

Author(s):

Elisa Morales Marroquin ◽

Emma Fletcher ◽

Paul Hwang ◽

Caelin S. Kim ◽

Noah Padgett ◽

...

Keyword(s):

Physical Activity ◽

Dietary Fiber ◽

Gut Microbiome ◽

Beta Diversity ◽

Alpha Diversity ◽

Anxiety And Depression ◽

Fiber Intake ◽

Microbial Composition ◽

Highly Active ◽

Dietary Fiber Intake

Abstract Background: Traditional thinking is that physical activity benefits mental and physical health, however, excessive physical activity can increase anxiety, depression, and affect the gut microbiome. Considering the strong connection between the gut and the brain, the purpose of the present study was to evaluate the association between gut microbiota composition and anxiety as well as depression in highly active individuals. Methods: Participants included 55 young adults (ages 18-25, 51% males). All participants were highly physically active, as determined by 7 days of SenseWear monitoring. Anxiety and depression were measured with the Beck Anxiety and Depression Inventories. Alpha diversity, beta diversity, and microbial composition were evaluated via 16S rRNA gene sequencing using distal gut samples. Results: Greater anxiety was associated with both lower distal gut alpha diversity ( P < 0.05) and higher beta diversity (PERMANOVA test; R-squared: 0.17562, P = 0.027), which appeared stronger in males. Genus level taxonomic abundance analysis showed Prevotella relative abundance as higher in males with higher anxiety ( P = 0.03, q=0.06). However, adjusted linear regression analysis, controlling for fiber intake and sex nullified the association between Prevotella and anxiety. Additional analysis demonstrated a strong association between lower dietary fiber intake and higher anxiety scores (Est.= -0.48, SE= 0.20 , P = 0.021). Conclusion: In highly active individuals, specifically males, there is a strong relationship between the gut microbiome, fiber intake, and anxiety. These data suggest highly active males with anxiety may benefit from increased dietary fiber intake.

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Body Mass Index Mediates the Association between Dietary Fiber and Symptomatic Knee Osteoarthritis in the Osteoarthritis Initiative and the Framingham Osteoarthritis Study

Journal of Nutrition ◽

10.1093/jn/nxy231 ◽

2018 ◽

Vol 148 (12) ◽

pp. 1961-1967 ◽

Cited By ~ 5

Author(s):

Zhaoli Dai ◽

S Reza Jafarzadeh ◽

Jingbo Niu ◽

David T Felson ◽

Paul F Jacques ◽

...

Keyword(s):

Body Mass Index ◽

Knee Osteoarthritis ◽

Dietary Fiber ◽

Body Mass ◽

Framingham Study ◽

Inverse Association ◽

Fiber Intake ◽

Symptomatic Knee Osteoarthritis ◽

Symptomatic Knee ◽

Osteoarthritis Initiative

ABSTRACT Background Dietary fiber reduces body weight and inflammation in clinical trials. It is unclear whether body mass index (BMI) and inflammation might explain the observed association between higher fiber intake and the lower risk of symptomatic knee osteoarthritis (SXKOA). Objectives We quantified the extent to which BMI and inflammation influenced the relation between dietary fiber and SXKOA. Methods We used longitudinal data from the Osteoarthritis Initiative (OAI) and the Framingham Offspring Osteoarthritis Study. At baseline of each study, men and women (mean age: 61 y) with or at risk of knee osteoarthritis were followed for 48 mo in the OAI. Adults (mean age: 53 y) were followed for 9.5 y in the Framingham study. Dietary fiber intake was estimated using a validated food-frequency questionnaire. Measured weight and height were used to calculate BMI. Serum high-sensitivity C-reactive protein (CRP) was measured in the Framingham study only. Incident SXKOA was defined as new onset of a combination of knee pain and radiographic osteoarthritis. We applied marginal structural models to quantify the mediation through BMI in the OAI and the sequential mediation through BMI and CRP in the Framingham study. Results Incident SXKOA occurred in 861 knees among 2876 persons in the OAI and in 143 knees among 971 persons in the Framingham study. In persons whose fiber intake was ≥21 g/d compared with those with intakes <21 g/d, the OR (95% CI) was 0.70 (0.53, 0.91) for the overall association with SXKOA and was 0.93 (0.92, 0.95) for the mediation via BMI (per kg/m2) in the OAI. In the Framingham study, the overall association was 0.57 (0.30, 1.09), the mediation through BMI (via BMI and the influence of BMI on CRP) was 0.94 (0.85, 1.02), and the mediation through CRP (per milligram per liter) was 0.99 (0.84, 1.19). Conclusion Our findings suggest that the inverse association of fiber intake and the risk of incident symptomatic knee osteoarthritis is partially mediated by BMI.

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