Effect of garlic extract on weight loss and gut microbiota composition in obese women: A double-blind randomized controlled trial

Abstract

ObjectiveFrom a nutritional perspective, garlic extract could be a prebiotic product, which is useful for obese subjects, and one of its health-promoting underlying mechanisms is modulating gut microbiota composition. In this randomized double-blind clinical trial, the goal was to determine the effect of Allium (garlic extract) on anthropometric indices and gut microbiota composition in obese women following a low-calorie diet.Materials and methodsForty-three obese women were randomly divided into garlic extract (400 mg Allium sativum powder containing 1,100 mcg allicin/tablet) or placebo groups. During the 2 months of the study, each participant took two tablets per day. At the beginning and at the end of the clinical trial, anthropometric measurements were done and blood and fecal samples were collected. We evaluated the gut microbiota composition using quantitative real-time PCR.ResultsIn total, 16 subjects in each group completed the 2-month trial. Allium and placebo groups’ participants had mean ages of 37.8 ± 7.4 and 34.2 ± 6.8 years, respectively (P > 0.05). Baseline body mass index (BMI) was significantly different between groups, subjects in the placebo group had lower BMI compared with the Allium group (P < 0.05). Allium and placebo caused a 1.7% and 2.7% decrease in BMI from the baseline values, respectively (P < 0.01). Fasting insulin level significantly decreased in the both groups (P < 0.01). Level of homeostasis model assessment of insulin resistance (HOMA-IR) has decreased significantly in the Allium group (P = 0.007). The frequency of Akkermansia had decreasing trend while the abundance of Faecalibacterium and Bifidobacterium showed increasing trend in the Allium group.ConclusionIn the both groups, a decrease in BMI and other anthropometric indices has been observed. Despite weight loss after following a low-calorie diet and taking Allium, slight changes have been shown in the composition of gut microbiota in obese women.Trial registrationThis trial was registered in the Iranian Registry of Clinical Trials (IRCT) (code: IRCT090420001825N2).

Prophybiotics for in-ovo stimulation; validation of effects on gut health and production of broiler chickens

“…The probiotic species used, L. mesenteroides is known to produce exopolysaccarides which display prebiotic properties ( Pan et al, 2020 ; Miyamoto et al, 2023 ) whereas garlic was previously reported as a rich source of fructans (70%–80% of dry weight) which also have proven prebiotic potential ( Lu et al, 2021 ). In the human gut, studies have shown an increased abundance of bacteria belonging to the Faecalibacterium ( Panyod et al, 2022 ) and Bifidobacterium ( Ettehad-Marvasti et al, 2022 ) genera in the presence of fructans. Therefore, it is possible that garlic aqueous extract has an additive or synergistic role in influencing changes in the microbiome when used in combination with L. mesenteroides.…”

Natural H2S‐donors: A new pharmacological opportunity for the management of overweight and obesity

“…The results of clinical studies on garlic extracts are controversial. In a very recent double‐blind clinical trial, 43 obese women were randomized to receive two garlic extract tablets (400 mg, containing 1.1 μg of allicin per tablet) or placebo per day (Ettehad‐Marvasti et al, 2022). At the end of the 2‐month intervention period, both placebo and garlic extract reduced BMI (by 2.7% and 1.7%, respectively), body weight, hip and waist circumference in obese women.…”