Daily Cashew and Brazil Nut Consumption Modifies Intestinal Health in Overweight Women on Energy-Restricted Intervention: A Randomized Controlled Trial (Brazilian Nuts Study).

BACKGROUND: Increased intestinal permeability and dysbiosis are related to obesity. Nuts can provide nutrients and bioactive compounds that modulate gut microbiota and inflammation, enhancing the beneficial effects of weight loss. OBJECTIVES: To evaluate the effect of consuming cashew nuts (Anacardium occidentale L.) and Brazil nuts (Bertholletia excelsa H.B.K) on intestinal permeability and microbiota, fecal SCFAs and pH, inflammation, and weight loss in energy restriction condition. METHODS: In this 8-week randomized controlled trial, 40 women with overweight or obesity were assigned to energy-restricted groups (-500 kcal/d): control group (free of nuts) or Brazilian nuts group (BN: 30 g of cashew nuts and 15 g of Brazil nuts per day). Permeability was analyzed by the lactulose/mannitol test and the microbiota by sequencing the 16S gene in the V3-V4 regions. Plasma concentrations of inflammatory cytokines (TNF, IL-6, IL-10, IL-8, IL-17A) and C-reactive protein were analyzed. RESULTS: In total, 25 women completed the intervention. Both groups lost weight without statistical differences. Lactulose excretion increased only in the control group (P < 0.05). The BN consumption increased fecal propionic acid and potentially beneficial bacteria, such as Ruminococcus, Roseburia, strains NK4A214 and UCG-002 from the Ruminococcaceae family, but also Lachnospiraceae family, Bacteroides, and Lachnoclostridium, when compared to the control group. Changes in intestinal permeability were correlated to a greater reduction in body fat (kg), and IL-8, and increases in Ruminococcus abundance. CONCLUSION: Our findings demonstrate a positive impact of BN consumption within an energy-restricted context, linked to the augmentation of potentially beneficial bacteria and pathways associated with body fat reduction. Besides, BN consumption mitigated increased intestinal permeability, although its capacity to diminish permeability or enhance weight loss proved limited. This trial was registered at the Brazilian Registry of Clinical Trials as ReBEC (ID: RBR-3ntxrm).

Bacterial Community Dynamics across the Gastrointestinal Tracts of Dairy Calves during Preweaning Development.

Microbial communities play critical roles in the gastrointestinal tracts (GIT) of preruminant calves by influencing performance and health. However, little is known about the establishment of microbial communities in the calf GIT or their dynamics during development. In this study, next-generation sequencing was used to assess changes in the bacterial communities of the rumen, jejunum, cecum, and colon in 26 crossbred calves at four developmental stages (7, 28, 49, and 63 days old). Alpha diversity differed among GIT regions with the lowest diversity and evenness in the jejunum, whereas no changes in alpha diversity were observed across developmental stage. Beta diversity analysis showed both region and age effects, with low numbers of operational taxonomic units (OTUs) shared between regions within a given age group or between ages in a given region. Taxonomic analysis revealed that several taxa coexisted in the rumen, jejunum, cecum, and colon but that their abundances differed considerably by GIT region and age. As calves aged, we observed lower abundances of taxa such as Bacteroides, Parabacteroides, and Paraprevotella with higher abundances of Bulleidia and Succiniclasticum in the rumen. The jejunum also displayed taxonomic changes with increases in Clostridiaceae and Turicibacter taxa in older calves. In the lower gut, taxa such as Lactobacillus, Blautia, and Faecalibacterium decreased and S24-7, Paraprevotella, and Prevotella increased as calves aged. These data support a model whereby early and successive colonization by bacteria occurs across the GIT of calves and provides insights into the temporal dynamics of the GIT microbiota of dairy calves during preweaning development.IMPORTANCE The gastrointestinal tracts (GIT) of ruminants, such as dairy cows, house complex microbial communities that contribute to their overall health and support their ability to produce milk. For example, the rumen microbiota converts feed into usable nutrients, while the jejunal microbiota provides access to protein. Thus, establishing a properly functioning GIT microbiota in dairy calves is critical to their productivity as adult cows. However, little is known about the establishment, maintenance, and dynamics of the calf GIT microbiota in early life. In this study, we evaluated the bacterial communities in the rumen, jejunum, cecum, and colon in dairy calves across preweaning development and show that they are highly variable early on in life before transitioning to a stable community. Understanding the dairy calf GIT microbiota has implications for ensuring proper health during early life and will aid in efforts to develop strategies for improving downstream production.