Perilla Oil, An Omega-3 Unsaturated Fatty Acid-Rich Oil, Enhances Diversity of Gut Microbiota and May Relieve Constipation in Sedentary Healthy Female: A Nonrandomized Placebo-Controlled Pilot Study

This study shows the effect of omega-3 unsaturated fatty acids via perilla oil intake on gut microbiota and constipation. Eight sedentary females participated in a nonrandomized placebo-controlled pilot study consisting of eight-week perilla oil (OIL) and placebo (PLA) intervention phases. There was a 10-month washout period between phases. All participants received 9 g of perilla oil-containing jelly in the OIL phase, and a placebo jelly in the PLA phase. Gut microbiota, α-diversity, and constipation scores were measured pre- and post-intervention in both phases. The α-diversity, an important indicator of gut microbiota diversity, was significantly increased post-intervention (4.5 ± 0.1) compared to pre-intervention (3.8 ± 0.3) in the OIL only (p = 0.021). Notably, the level of α-diversity was maintained even after the washout period of 10 months. Butyrate-producing bacteria, Lachnospiraceae (%), did not change in the OIL but were significantly reduced post-intervention (15.1 ± 4.8) compared to pre-intervention (20.1 ± 7.0) in the PLA (p = 0.040). In addition, the constipation scores were significantly or tended to be reduced during the OIL phase only (p < 0.05, p < 0.1). In conclusion, an eight-week perilla oil supplementation may enhance and establish the diversity of gut microbiota, which may relieve constipation.