Effects of yacon flour associated with an energy restricted diet on intestinal permeability, fecal short chain fatty acids, oxidative stress and inflammation markers levels in adults with obesity or overweight: a randomized, double blind, placebo controlled clinical trial

Abstract

Objectives Yacon flour is rich in bioactive compounds (phenolic compounds and fructooligosaccharides (FOS)), and may therefore reduce the risk of diseases associated with excess body weight. However, its effect on fecal short chain fatty acids (SCFA), intestinal permeability, oxidative stress and inflammation markers has not been studied in adult humans with excess body weight. Thus, we evaluated the effect of the consumption of yacon flour on these variables. Materials and methods Twenty-six excess body weight (30.4 ± 2.4 kg/m 2 ) adults (31.3 ± 8.5y) were randomized to one of two groups (yacon flour or control; n = 13) on a double blind clinical trial. Subjects received a breakfast drink containing or not yacon flour (25g) associated with an energy restricted diet, for six weeks. The flour chemical characterization, FOS and total phenolics contents were evaluated. Antioxidant capacity was evaluated in vitro and in vivo (plasma). Intestinal permeability, fecal SCFA, oxidative stress and inflammatory markers also were evaluated in vivo. Results Yacon flour was well tolerated. It presented an in vitro and in vivo antioxidant capacity, increased plasma total antioxidant capacity (Δ YAC : 49.16 (-4.20; 156.63)) and reduced protein carbonyl concentrations (Δ YAC : -0.98 (-1.54; -0.42)). A reduction in SCFAs was observed in both groups (Δ acetic : -3.16 (-5.07; -0.95) vs. -1.05 (-2.65; 1.11); Δ propionic : -1.05 (-2.60;-0.38) vs. -0.41 (-2.08; 0.09); Δ butyric : -0.75 (-1.38; -0.04) vs. -0.28 (-0.98; 0.11), for YAC and CON, respectively). Other variables did not change. Conclusion The yacon flour increased the plasma antioxidant capacity, decreased oxidative stress and SCFAs in adults with obesity or overweight.

Effects and Mechanisms of Probiotics, Prebiotics, Synbiotics, and Postbiotics on Metabolic Diseases Targeting Gut Microbiota: A Narrative Review

“…The intake of prebiotic foods has been recognized as a potential treatment for obesity [ 105 ]. The clinical trials showed that the daily intake of yacon (a natural source of phenolic compounds and fructo-oligosaccharides) at a dose of 25 g for 6 weeks could increase the plasma antioxidant capacity, while decrease oxidative stress and fecal SCFAs levels in obese patients with no severe side effects [ 106 , 107 ]. Moreover, a clinical trial on 42 overweight and obese children showed that the consumption of oligofructose-enriched inulin at doses of 8 g/day for 16 weeks reduced energy intake by regulating appetite [ 108 ].…”

Influence of Smallanthus sonchifolius (Yacon) on the Activity of Antidepressant Drugs in Mice

“…Additionally, it elevated values of glutathione peroxidase and glutathione in the liver and kidneys, and it normalized the composition of liver fatty acids along with cholesterol and triacylglycerol levels in plasma [53]. In the double-blind placebocontrolled clinical trial, a 6-week consumption of Yacon flour resulted in antioxidant activity, and it increased the plasma total antioxidant capacity [41]. In the recent study by Baek et al [54], it was demonstrated that the Yacon leaf extract produced a significant neuroprotective effect in the lipopolysaccharide-induced mouse model of neuroinflammation by reducing mRNA expression of the inflammatory factors, including inducible nitric oxide synthase, cyclooxygenase-2, interleukin 1β, and tumor necrosis factor (TNF)-α.…”

“…Though our experiments did not assess the molecular mechanism of the antidepressantlike activity of Yacon tuber extract, we guess that it can be at least partially caused by the antioxidant [10,41], anti-inflammatory, and probiotic properties of its main components, particularly fructooligosaccharides, inulin, polyphenols, and tryptophan. It would be in line with new theories of depression, which associate the development of this disease with oxidative stress [50], (neuro)inflammation [51], and disturbances in the gut-microbiotabrain axis [52].…”

“…It is particularly significant given the safety profile of Yacon preparations. Reports from clinical trials confirmed that Yacon products are generally well tolerated by patients [23,25,26,41], though the daily intake of Yacon syrup containing 20 g of fructooligasaccharides/70 kg body weight/day may induce gastrointestinal adverse effects, including diarrhea, severe abdominal distention, flatulence, and nausea [23]. One case report on the anaphylactic reaction due to ingestion of Yacon root can be found in the medical literature [42].…”

The effect of fibre intervention on serum and faecal short-chain fatty acids in human with overweight or obesity: a systematic review of human intervention studies

“…Thus, a total of 17 studies were included in the qualitative synthesis (Table 1). 18,19,[35][36][37][38][39][40][41][27][28][29][30][31][32][33][34] The majority of studies (14 studies) included both sexes (male and female); the remaining three studies only included male (2 studies) or female (1 study) participants. BMI cut-offs vary between studies, 1 study included participants with BMI <28.7 kg/m 2 , 27 1 study with BMI ≤32 kg/m 2 , 29 and the remaining studies (15 studies) included BMI ranging from 25 -45 kg/m 2 .…”