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.

2021-05-01
Archives of endocrinology and metabolism 64(5)
- Adriane Moreira Machado
- Nayara Benedito Martins da Silva
- Renata Maria Pereira de Freitas
- Mariella Bontempo Duca de Freitas
- José Bemício Paes Chaves
- Leandro Licursi Oliveira
- Hércia Stampini Duarte Martino
- Rita de Cássia Gonçalves Alfenas

PubMed: 34033301
DOI: 10.20945/2359-3997000000225

Study Design

Type: Randomized Controlled Trial (RCT)
Sample size: n = 13
Population: Twenty-six excess body weight (30.4 ± 2.4 kg/m^2) adults (31.3 ± 8.5y)
Methods: double blind clinical trial; subjects received a breakfast drink containing or not yacon flour (25g) associated with an energy restricted diet, for six weeks
Blinding: Double-blind
Duration: six weeks
Funding: Unclear

Objective

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.

Methods

Twenty-six excess body weight (30.4 ± 2.4 kg/m²) 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.

Research Insights

Yacon→Improved Intestinal Epithelial Permeability
Other variables did not change.
Effect
Neutral
Effect size
Small
Dose
25 g/day
Yacon→Increased Short-Chain Fatty Acid Levels
A reduction in SCFAs was observed in both groups (Δacetic: -3.16 (-5.07; -0.95) vs. -1.05 (-2.65; 1.11); Δpropionic: -1.05 (-2.60;-0.38) vs. -0.41 (-2.08; 0.09); Δbutyric -0.75 (-1.38; -0.04) vs. -0.28 (-0.98; 0.11), for YAC and CON, respectively). Other variables did not change.
Effect
Neutral
Effect size
Small
Dose
25 g/day
Yacon→Reduced Inflammatory Markers
Other variables did not change.
Effect
Neutral
Effect size
Small
Dose
25 g/day
Yacon→Reduced Oxidative Stress
increased plasma total antioxidant capacity (ΔYAC: 49.16 (-4.20; 156.63)) and reduced protein carbonyl concentrations (ΔYAC: -0.98 (-1.54; -0.42))
Effect
Beneficial
Effect size
Moderate
Dose
25 g/day

Adverse Events Reported

Yacon→Overall tolerability
Yacon flour was well tolerated.
Finding
Reported