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Almond Consumption and Processing Affects the Composition of the Gastrointestinal Microbiota of Healthy Adult Men and Women: A Randomized Controlled Trial.
Holscher, HD, Taylor, AM, Swanson, KS, Novotny, JA, Baer, DJ
Nutrients. 2018;10(2)
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Poor diet is recognised as a contributing factor to the development of common diseases, such as type 2 diabetes, cardiovascular disease and obesity. Increasingly, links are being made between the health and diversity of the human intestinal microbiome (the bacteria resident in our gut) and these chronic metabolic disorders. The microbiome is constantly changing, depending on a number of factors, including dietary intake. This small cross-over study of 18 participants, included five three-week diet periods of almonds in varying forms, with a one week break (wash out) between diets. The diets were 1. No almonds; 2. 42g whole almonds daily; 3. 42g whole roasted almonds daily; 4. 42g roasted, chopped almonds daily and 5. 42g of almond nut butter. Using stool samples at the end of each diet period, the results showed that chopped almond consumption increased the relative abundance of 3 bacteria strains (Lachnospira, Roseburia and Oscillospira) compared to the no almonds control group, while whole almonds increased the Dialister bacteria strain compared to control. There were no differences between the almond nut butter and control. The authors conclude that consumption of almonds affects the intestinal bacteria profile, which differs with the form of almonds eaten. Whilst this is a small study, Nutrition Practitioners should be aware of the ability to manipulate the gut microbiome with targeted dietary changes.
Abstract
BACKGROUND Almond processing has been shown to differentially impact metabolizable energy; however, the effect of food form on the gastrointestinal microbiota is under-investigated. OBJECTIVE We aimed to assess the interrelationship of almond consumption and processing on the gastrointestinal microbiota. DESIGN A controlled-feeding, randomized, five-period, crossover study with washouts between diet periods was conducted in healthy adults (n = 18). Treatments included: (1) zero servings/day of almonds (control); (2) 1.5 servings (42 g)/day of whole almonds; (3) 1.5 servings/day of whole, roasted almonds; (4) 1.5 servings/day of roasted, chopped almonds; and (5) 1.5 servings/day of almond butter. Fecal samples were collected at the end of each three-week diet period. RESULTS Almond consumption increased the relative abundances of Lachnospira, Roseburia, and Dialister (p ≤ 0.05). Comparisons between control and the four almond treatments revealed that chopped almonds increased Lachnospira, Roseburia, and Oscillospira compared to control (p < 0.05), while whole almonds increased Dialister compared to control (p = 0.007). There were no differences between almond butter and control. CONCLUSIONS These results reveal that almond consumption induced changes in the microbial community composition of the human gastrointestinal microbiota. Furthermore, the degree of almond processing (e.g., roasting, chopping, and grinding into butter) differentially impacted the relative abundances of bacterial genera.
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Substituting whole grains for refined grains in a 6-wk randomized trial has a modest effect on gut microbiota and immune and inflammatory markers of healthy adults.
Vanegas, SM, Meydani, M, Barnett, JB, Goldin, B, Kane, A, Rasmussen, H, Brown, C, Vangay, P, Knights, D, Jonnalagadda, S, et al
The American journal of clinical nutrition. 2017;105(3):635-650
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Increased whole grain consumption has been associated with reduced levels of inflammation. This randomised, controlled trial aimed to assess the effects of a whole grain diet in comparison with a refined grain diet on the immune system, levels of inflammation and gut bacteria. 81 men and women aged between 40 and 60 were randomly assigned to either a whole grain or a refined grain diet for a period of 6 weeks. All other dietary components were kept the same and calorie levels were controlled to maintain weight levels. The study findings showed a positive effect on stool frequency and stool weight with the whole grain diet in comparison to the refined grain diet. The whole grain diet also showed modest positive effects on gut bacteria profiles and aspects of immunity. The whole grain diet showed no effects on markers of inflammation.
Abstract
Background: Observational studies suggest an inverse association between whole-grain (WG) consumption and inflammation. However, evidence from interventional studies is limited, and few studies have included measurements of cell-mediated immunity.Objective: We assessed the effects of diets rich in WGs compared with refined grains (RGs) on immune and inflammatory responses, gut microbiota, and microbial products in healthy adults while maintaining subject body weights.Design: After a 2-wk provided-food run-in period of consuming a Western-style diet, 49 men and 32 postmenopausal women [age range: 40-65 y, body mass index (in kg/m2) <35] were assigned to consume 1 of 2 provided-food weight-maintenance diets for 6 wk.Results: Compared with the RG group, the WG group had increased plasma total alkyresorcinols (a measure of WG intake) (P < 0.0001), stool weight (P < 0.0001), stool frequency (P = 0.02), and short-chain fatty acid (SCFA) producer Lachnospira [false-discovery rate (FDR)-corrected P = 0.25] but decreased pro-inflammatory Enterobacteriaceae (FDR-corrected P = 0.25). Changes in stool acetate (P = 0.02) and total SCFAs (P = 0.05) were higher in the WG group than in the RG group. A positive association was shown between Lachnospira and acetate (FDR-corrected P = 0.002) or butyrate (FDR-corrected P = 0.005). We also showed that there was a higher percentage of terminal effector memory T cells (P = 0.03) and LPS-stimulated ex vivo production of tumor necrosis factor-α (P = 0.04) in the WG group than in the RG group, which were positively associated with plasma alkylresorcinol concentrations.Conclusion: The short-term consumption of WGs in a weight-maintenance diet increases stool weight and frequency and has modest positive effects on gut microbiota, SCFAs, effector memory T cells, and the acute innate immune response and no effect on other markers of cell-mediated immunity or systemic and gut inflammation. This trial was registered at clinicaltrials.gov as NCT01902394.
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Effects of milk containing only A2 beta casein versus milk containing both A1 and A2 beta casein proteins on gastrointestinal physiology, symptoms of discomfort, and cognitive behavior of people with self-reported intolerance to traditional cows' milk.
Jianqin, S, Leiming, X, Lu, X, Yelland, GW, Ni, J, Clarke, AJ
Nutrition journal. 2016;15:35
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Cows’ milk contains two types of beta-casein, A1 and A2, and the A1 type is thought to cause the adverse gastrointestinal side effects related to lactose intolerance. The aim of this crossover study was to compare the effects of milk consumption with differing beta-casein types in subjects with self-reported lactose intolerance. Forty-five participants were randomised to receive milk containing either both types of casein or only the A2 type, and inflammatory markers, symptoms of digestive discomfort and cognitive processing were assessed. This study demonstrated that consumption of milk containing A1 beta-casein was associated with increased inflammation, worsening of digestive discomfort, delayed transit and decreased cognitive functioning. The findings of this study suggest that some symptoms of lactose intolerance may be attenuated by consuming milk containing only the A2 type of beta-casein.
Abstract
BACKGROUND Cows' milk generally contains two types of β-casein, A1 and A2 types. Digestion of A1 type can yield the peptide β-casomorphin-7, which is implicated in adverse gastrointestinal effects of milk consumption, some of which resemble those in lactose intolerance. This study aimed to compare the effects of milk containing A1 β-casein with those of milk containing only A2 β-casein on inflammation, symptoms of post-dairy digestive discomfort (PD3), and cognitive processing in subjects with self-reported lactose intolerance. METHODS Forty-five Han Chinese subjects participated in this double-blind, randomized, 2 × 2 crossover trial and consumed milk containing both β-casein types or milk containing only A2 β-casein. Each treatment period was 14 days with a 14-day washout period at baseline and between treatment periods. Outcomes included PD3, gastrointestinal function (measured by smart pill), Subtle Cognitive Impairment Test (SCIT), serum/fecal laboratory biomarkers, and adverse events. RESULTS Compared with milk containing only A2 β-casein, the consumption of milk containing both β-casein types was associated with significantly greater PD3 symptoms; higher concentrations of inflammation-related biomarkers and β-casomorphin-7; longer gastrointestinal transit times and lower levels of short-chain fatty acids; and increased response time and error rate on the SCIT. Consumption of milk containing both β-casein types was associated with worsening of PD3 symptoms relative to baseline in lactose tolerant and lactose intolerant subjects. Consumption of milk containing only A2 β-casein did not aggravate PD3 symptoms relative to baseline (i.e., after washout of dairy products) in lactose tolerant and intolerant subjects. CONCLUSIONS Consumption of milk containing A1 β-casein was associated with increased gastrointestinal inflammation, worsening of PD3 symptoms, delayed transit, and decreased cognitive processing speed and accuracy. Because elimination of A1 β-casein attenuated these effects, some symptoms of lactose intolerance may stem from inflammation it triggers, and can be avoided by consuming milk containing only the A2 type of beta casein. TRIAL REGISTRATION ClinicalTrials.gov/NCT02406469.
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Synbiotic therapy decreases microbial translocation and inflammation and improves immunological status in HIV-infected patients: a double-blind randomized controlled pilot trial.
González-Hernández, LA, Jave-Suarez, LF, Fafutis-Morris, M, Montes-Salcedo, KE, Valle-Gutierrez, LG, Campos-Loza, AE, Enciso-Gómez, LF, Andrade-Villanueva, JF
Nutrition journal. 2012;11:90
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HIV causes gastrointestinal dysfunction and microbial translocation that can provoke local and systemic inflammation that may lead to disease progression. Inflammation and intestinal permeability increase and the reduction in immune defences creates the opportunity for microbial overgrowth and raised lipopolysaccharides levels, which may lead to disease progression. HIV-infected patients also tend to have low levels of beneficial bacteria. Probiotics have the potential to stimulate the immune system through IgA secretion and reduce inflammation. Prebiotics selectively stimulate the growth of some bacteria, altering the composition and metabolic activity of gut microbiota. This randomized, prospective, double-blind controlled pilot study evaluates use of probiotics and prebiotic to expand beneficial microbiota that help decrease bacterial translocation and pro-inflammatory cytokine production, thereby improving immune functions in HIV-infected subjects. 20 HIV-infected adult patients were divided into four groups (n=5 per group) to receive probiotics, synbiotic, a prebiotic, or placebo once daily for 16 weeks. Probiotics used were Lactobacillus rhamnosus plus Bifidobacterium lactis. From baseline to week 16, the synbiotic group showed a reduction in bacterial DNA concentrations in plasma. The probiotic and synbiotic groups demonstrated a decrease in total bacterial load in feces. The probiotic group showed a significant increase in beneficial bacteria load (such as Bifidobacterium and a decrease in harmful bacteria load (such as Clostridium). The synbiotic group had greater increases in CD4+ T-cell count and cytokine levels (IL-6) decreased significantly. Serious adverse effects previously reported with the use of probiotics in immunocompromised patients were not reported in this study. The authors found no decrease in HIV-1 plasma viral load so the use of a synbiotic for maintaining an undetectable viral load as part of the primary prevention of HIV transmission is not justified.
Abstract
BACKGROUND HIV-infection results in damage and dysfunction of the gastrointestinal system. HIV enteropathy includes pronounced CD4+ T-cell loss, increased intestinal permeability, and microbial translocation that promotes systemic immune activation, which is implicated in disease progression. A synbiotic is the combination of probiotics and prebiotics that could improve gut barrier function. Our study goal was to determine whether the use of a synbiotic, probiotics or a prebiotic can recover immunological parameters in HIV-infected subjects through of a reduction of microbial translocation and pro-inflammatory cytokine production. METHODS A randomized, double-blind controlled study was performed; twenty Antiretroviral treatment-naïve HIV-infected subjects were subgrouped and assigned to receive a synbiotic, probiotics, a prebiotic, or a placebo throughout 16 weeks. RESULTS We had no reports of serious adverse-events. From baseline to week 16, the synbiotic group showed a reduction in bacterial DNA concentrations in plasma (p = 0.048). Moreover, the probiotic and synbiotic groups demonstrated a decrease in total bacterial load in feces (p = 0.05). The probiotic group exhibited a significant increment of beneficial bacteria load (such as Bifidobacterium; p = 0.05) and a decrease in harmful bacteria load (such as Clostridium; p = 0.063). In the synbiotic group, the CD4+ T-cells count increased (median: +102 cells/μL; p = 0.05) and the level of Interleukin 6 cytokine decreased significantly (p = 0.016). CONCLUSIONS Our study showed a significant increase in CD4+ T lymphocyte levels in the synbiotic group, which could delay the initiation of antiretroviral therapy and decrease costs in countries with limited resources.