Constipation is a widespread health concern across regions and age groups, with chronic constipation significantly impacting quality of life and healthcare systems globally.
Defined as infrequent bowel movements lasting over three months, it is prevalent in 9% to 29% of adults worldwide.
It often leads to complications like haemorrhoids and anal fissures, imposing financial and emotional burdens on affected individuals.
Current treatments include lifestyle changes, dietary adjustments, and laxatives.
However, concerns over the overuse of laxatives have shifted the focus toward natural, sustainable interventions like dietary fibres.
In fact, recent advancements in gut health research have highlighted their potential — specifically, that of resistant starches — to ease constipation.
Researching resistant starches
Based on this, researchers at Mahidol University conducted a double-blind, placebo-controlled randomised clinical trial (RCT) to evaluate the impact of resistant starch type 3 (RS-3) on gut microbiota and bowel movements in Thai adults with chronic constipation.
Resistant starch (RS), a type of dietary fibre that resists digestion in the small intestine but ferments in the large intestine, has emerged as a promising alternative.
Among the five types of RS, RS-3 stands out for its ability to support beneficial gut bacteria and produce short-chain fatty acids (SCFAs), which are crucial for gut health.
The trial aimed to assess the effects of RS-3 on gut microbiota composition, stool frequency, and stool consistency in adults with self-reported chronic constipation.
Ninety-eight participants were randomised to receive either RS-3 or a placebo for 12 weeks. The RS-3 product, derived from natural sources such as ginkgo nut, spinach, corn, and brown rice, was consumed daily.
Participants maintained their usual diets and physical activity levels throughout the study. Faecal samples were collected and analysed using advanced metagenomic sequencing to evaluate changes in gut microbiota.
Improved stool frequency and gut health
The results highlighted several significant outcomes for participants consuming RS-3, such as enhanced stool frequency and consistency, alleviation of constipation symptoms, and positive gut microbiota changes.
After 12 weeks, participants in the RS-3 group reported an increase in bowel movement frequency, with most achieving four to five movements per week.
Their Bristol Stool Scale (BSS) scores improved significantly, indicating healthier stool consistency (smooth and easy-to-pass stools).
Participants consuming RS-3 also reported lower scores on the Constipation Scoring System (CSS), reflecting reduced symptoms such as abdominal pain and incomplete evacuation.
Additionally, they saw an increase in the diversity and abundance of beneficial bacteria, including Bifidobacterium, Prevotella, Akkermansia, and Megamonas.
These bacteria are known to produce SCFAs like butyrate, acetate, and propionate, which enhance gut health by promoting intestinal barrier function, reducing inflammation, and improving motility.
This pointed to the prebiotic potential of RS-3, and with SCFAs critical for maintaining gut homeostasis, fuelling colon cells, and regulating gut motility, the rise in SCFA levels in the RS-3 group aligned with improved bowel movement frequency and stool quality.
Compared to traditional prebiotics like inulin, RS-3 demonstrated a unique ability to produce higher levels of butyrate, a key SCFA.
This characteristic means RS-3 could be a superior option for supporting gut health and alleviating constipation without causing excessively soft stools, a common issue with some fibres.
Furthermore, the researchers observed in the supplemented group a favourable shift in the Firmicutes-to-Bacteroidota (F/B) ratio, which has been linked to better gut health.
Practical implications for businesses and healthcare providers
The findings from this trial present RS-3 as a viable dietary intervention for managing constipation. Businesses in the nutraceutical, functional food, and dietary supplement industries can explore RS-3 as a core ingredient in gut health products.
Healthcare providers may also recommend RS-3 supplementation as a natural, evidence-based alternative to traditional laxatives.
Key considerations for commercialization include formulation, education, and compliance.
In terms of formulation, RS-3 can be incorporated into powders, capsules, or ready-to-eat products.
However, this must be preceded by raising awareness among healthcare professionals and consumers about the benefits of RS-3.
Moreover, to maximise adherence, products containing RS-3 must be palatable and easy to consume.
A step forward in gut health management
This study reinforces the prebiotic potential of RS-3, demonstrating its ability to improve bowel function, alleviate constipation symptoms, and enhance gut microbiota diversity.
However, the researchers also concluded: “While this study demonstrated the prebiotic potential of RS-3, additional research comparing the benefits of RS-3 to other RS forms will provide deeper comprehension of their comparative characteristics.
“Additional studies of the host benefits of RS-3 supplementation and the underlying mechanisms by which RS-3 exhibits its prebiotic effects and promotes host health will be useful in developing personalised treatment for patients with constipation to achieve optimal health outcomes.”
Source: National Center for Biotechnology Information
“Impact of resistant starch type 3 on fecal microbiota and stool frequency in Thai adults with chronic constipation randomized clinical trial”
https://doi.org/10.1038/s41598-024-79465-1
Authors: Sirirat Luk-In, et al.
