Researchers in Japan investigated the effects of Lactobacillus paragasseri (L paragasseri) OLL2716 on healthy adults with gastric discomfort in a randomised, double-blind, placebo-controlled trial, and found that they reported less stomach discomfort and improved mental health after 12 weeks.
“The results suggest that regular intake of L paragasseri OLL2716 may improve both gastric discomfort and mental stress in healthy adults with gastric complaints, such as postprandial fullness or early satiety,” wrote researchers in Nutrients.
Previous research showed that stress can delay gastric emptying, leading to upper gastrointestinal symptoms. Furthermore, the brain and stomach communicate bidirectionally through the autonomic nervous system, meaning that stress influences digestive function, while gastrointestinal discomfort, such as excess stomach acid or pain, exacerbates stress.
“According to epidemiological studies, 50% of functional gastroenteropathies are caused by psychological stress, whereas the remaining 50% are caused by gastrointestinal tract dysfunction. Although the cause-and-effect relationship remains unclear, maintaining both mental health and normal stomach function is essential,” researchers said.
Recent studies have highlighted the positive effects of certain probiotic strains on gastrointestinal health and discomfort. Specifically, the L paragasseri OLL2716 strain has demonstrated benefits for the gut-brain axis.
This study therefore aims to evaluate the effects of OLL2716 on gastric discomfort and mental stress in healthy adults experiencing gastric complaints.
Yoghurt with probiotics
For the 12-week trial, 174 healthy adults from 20–64 years old were recruited from eight hospitals and clinics across Japan.
Participants were randomly assigned to two equal groups where they had to eat a daily serving of 85g yoghurt for 12 weeks.
The OLL2716 group ingested yogurt containing L paragasseri OLL2716, with at least 109 colony-forming units of L paragasseri OLL2716 per serving.
The placebo group ingested yoghurt that consisted of raw milk, dairy products, sugar, stevia, and water fermented with Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus.
Both types of yoghurt had the same nutritional profile with 68kcal energy, 2.9g protein, 2.6g fat, 8.3g carbohydrate, and 102mg calcium. They were also identical in flavour and appearance.
Symptoms were assessed at the 6-week and 12-week points through questionnaires.
Relief for gastric symptoms and mental health
For the OLL2716 group, epigastric pain was significantly decreased at 6 weeks by −0.5 ± 1.3 points and by −0.7 ± 1.2 points at 12 weeks.
This was a significant improvement compared to the placebo group, which showed a decrease by −0.1 ± 1.3 points at 6 weeks and −0.2 ± 1.4 points at 12 weeks.
Indicators of mental stress also showed greater improvement in the OLL2716 group compared to the placebo group, according to the short-form Nepean Dyspepsia Index (SF-NDI), which assesses the relationship between gastric complaints and the quality of life, including mental stress.
For example, the OLL2716 group showed a decrease of 0.5 ± 0.6 points for “irritable, tense, or frustrated” at week 6, compared to the placebo group which showed a decrease of 0.3 ± 0.7 points.
The OLL2716 group also showed a significant decrease of 0.7 ± 1.1 points for “tension” at week 6, compared to the placebo group which showed a decrease of 0.4 ± 1.3 points.
As for the Gastrointestinal Symptom Rating Scale, the number of participants with improved overall scores at 12 weeks was significantly greater in the OLL2716 group at 44.8% compared to the placebo group, which stood at 28.7%.
Participants in the OLL2716 group also showed a significantly greater improvement in appetite compared to the placebo group as assessed by the Council on Nutrition Appetite Questionnaire-Japanese – at week 12, the OLL2716 score improved by 0.9 ± 2.4 points, while the placebo group score improved by 0.4 ± 2.3 points.
No adverse effects were observed in either group.
“The efficacy of L. paragasseri OLL2716 was not limited to gastrointestinal symptoms such as stomach pain and EPS-like symptoms but also affected stress and appetite. These improvements were considered to be due to the consumption of yogurt containing L. paragasseri OLL2716, which alleviated gastrointestinal symptoms such as stomach pain and subsequently led to reduced stress and improved appetite,” said researchers.
The findings suggest that regular intake of L paragasseri OLL2716 may improve both gastric discomfort and mental stress in healthy adults with gastric complaints such as postprandial fullness or early satiety, concluded the researchers.
However, while researchers have suggested that L paragasseri OLL2716 may work by regulating autonomic function, more studies are needed to fully understand its mechanism of action.
Source: Nutrients
DOI: https://doi.org/10.3390/nu16183188
“The Beneficial Effects of Regular Intake of Lactobacillus paragasseri OLL2716 on Gastric Discomfort in Healthy Adults: A Randomized, Double-Blind, Placebo-Controlled Study”
Authors: Naruomi Yamada, Kyosuke Kobayashi et al.