Kombucha is a fermented nonalcoholic tea-based beverage produced through a symbiotic culture of bacteria and yeasts. In vitro studies have demonstrated antimicrobial, antioxidant, antiproliferative, and anti-carcinogenic properties of kombucha. However, no systematic reviews have evaluated the effects of kombucha in vivo. Thus, we aimed to evaluate the evidence that exists so far about kombucha consumption on comorbidities associated with obesity as well as on the gut microbiota. The search was conducted in accordance with PRISMA and the protocol was registered in PROSPERO (registration number: CRD42020158917). The MEDLINE/PubMed, Web of Science, LILACS, SciELO, Scopus, and Science Direct databases were used in the search considering the following terms: “kombucha” OR “kombucha tea” OR “kombucha teas” OR “tea, kombucha” OR “teas, kombucha” NOT “review.” Fifteen studies were included in this review. The results suggest that kombucha consumption attenuates oxidative stress and inflammation, improves the liver detoxification process, and reduces intestinal dysbiosis. There is evidence that kombucha consumption is beneficial for the control and treatment of obesity and associated comorbidities, as well as for the modulation of the gut microbiota in vivo.

Kombuchas from green and black teas are rich sources of phenolic compounds that reduced the metabolic changes induced by HFHF diet.

The Western diet can negatively affect the gut microbiota and is associated with metabolic disorders. Kombucha, a tea fermented by a symbiotic culture of bacteria and yeast (SCOBY), is known for its bioactive properties and has become popular in the last years. In this study, we evaluated the effects of regular kombucha consumption on the gut microbiota and on outcomes related to the intestinal health of Wistar rats fed a high-fat high-fructose diet. After eight weeks receiving a standard diet (AIN-93M) (n = 10) or a high-fat and high-fructose diet (HFHF) (n = 30) to induce metabolic disorders, the animals were subdivided into four groups: AIN-93M (n = 10); HFHF (n = 10); GTK (HFHF + green tea kombucha (n = 10); and BTK (HFHF + black tea kombucha; n = 10) for 10 weeks. Although body composition did not differ among the groups, the HFHF diet was associated with metabolic alterations, and stimulated the growth of gram-negative bacteria such as Proteobacteria and Bacteroides. Kombucha ingestion could somewhat modulate the gut microbiota, attenuating the effects of a Western diet by increasing propionate production and favoring the growth of beneficial bacteria, such as Adlercreutzia in the GTK group. Our results suggest that regular kombucha consumption may be beneficial to intestinal health, which can be mostly attributed to its high content and diversity of phenolic compounds.

Context: Consumption of dietary advanced glycation end products (AGEs) is associated with oxidative stress, inflammation, and other chronic conditions commonly associated with obesity. Objective: To analyze the effects of dietary AGEs on complications associated with obesity. Data sources: This systematic review was conducted and reported according to PRISMA guidelines. The PubMed, Cochrane, and Scopus databases were searched, using the terms “advanced glycation end products,” “overweight,” and “obesity.” The last search was performed in October 2018. Data extraction: Six studies that evaluated the effects of low-AGE and high-AGE diets were included in the review. The duration of the studies ranged from 1 day to 12 weeks. A comparison of all the compiled data was conducted by the authors. Data analysis: Circulating and urinary AGE markers, besides soluble receptor for AGEs, were considered as the primary outcomes. The secondary outcomes were cardiometabolic, inflammatory, glycemic, anthropometric, and renal markers. Conclusions: AGE-RAGE interactions can activate the NF-κB (nuclear factor kappa B) signaling pathway and inhibit the PI3K-AKT pathway in adipocytes, which may explain their association with chronic diseases. This interaction can be considered as a novel explanation for the pathogenesis of obesity. AGEs can also be used as a biomarker for monitoring responses to dietary interventions in overweight and obese people. Systematic Review Registration: PROSPERO registration no. CRD42018082745.

Background: Kombucha, a fermented tea, has been suggested as an adjuvant in the treatment of obesity. Although animal and in vitro studies indicate its promising benefits, exploring kombucha’s impact on human health is necessary. Methods: This quasi-experimental pre–post-intervention assessed the effect of black tea kombucha consumption on cardiometabolic parameters for 8 weeks, considering the quality of the diet of individuals with and without obesity. Diet quality was assessed through the Dietary Inflammatory Index^® and Dietary Total Antioxidant Capacity. Paired t-test/Wilcoxon was applied to compare differences between pre- and post-intervention (α = 0.05). Results: After the intervention, individuals with obesity showed a decrease in insulin, HOMA-IR, and GGT; those without obesity showed an increase in total cholesterol and alkaline phosphatase, but this was only observed in those with a worsened diet quality. Conclusion: kombucha intake demonstrated positive impacts on the metabolic health of individuals with obesity beyond the importance of combining it with healthy eating patterns.

Nuts are important sources of antioxidants that combat oxidative stress and improve lipid profile as well as vascular function. However, the intake of typical Brazilian nuts and its acute effect on cardiovascular health needs to be better understood. Thus, the present study aimed to evaluate the acute effect of a beverage containing cashew ( Anacardium occidentale L.) and Brazil nuts ( Bertholletia excelsa H.B.K.) on postprandial oxidative stress, lipemia, and blood pressure of adult women aged 20 to 55 years with cardiometabolic risk. This was an acute, randomized, parallel arm, controlled clinical trial. The participants received either a beverage containing nuts (30 g Brazil nuts + 15 g cashew nuts) or a beverage without nuts with similar macronutrient composition. Oxidative stress markers and lipid profiles were evaluated at fasting and 4 h after beverage consumption. Blood pressure was measured during fasting and after beverage intake (1, 2, 3, and 4 h). In the postprandial state, there was a greater reduction in malondialdehyde levels in the intervention group compared to the control group (−12.3 ± 0.59 vs. −10.7 ± 0.43 µmol/mL; p < 0.05), which was positively correlated with the concentrations of TG ( r = 0.399; p < 0.05), VLDL ( r = 0.399; p < 0.05), TG/HDL ( r = 0.380; p < 0.05), and blood pressure (iAUC SBP r = 0.391; p < 0.05, iAUC DBP r = 0.409; p < 0.05). The remaining oxidative stress markers showed similar postprandial changes between groups. In women with cardiometabolic risk, a beverage containing Brazilian nuts promoted a significant acute reduction on postprandial malondialdehyde levels. The study was registered in the Brazilian Clinical Trials Registry—ReBEC (protocol: RBR-3ntxrm).