The role of dietetics in gut health

The idea of ‘gut health’ seems to be everywhere, but the popularisation of ‘gut health’ by food industry and popular media appears to have overtaken what we actually know from science, writes Dr Georgina Williams*, an accredited practising dietitian and postdoctoral researcher in diet and gastroenterology at the NHMRC Centre for Research Excellence in Digestive Health.

The past 20 years have seen rapid scientific advances in our knowledge of the gut, including an ever-increasing awareness of the bugs that live there, known as our ‘microbiome’.

Despite this, scientists are still trying to understand what ‘gut health’ really means, and it appears to be much more complicated than we first thought. We know that certain types of gut microbes and their actions may benefit health; however, each individual’s gut health likely looks different and is influenced by genetics, diet and environmental factors such as whether we own a pet or spend time in nature.

For health professionals, the promise of being able to work with clients to improve gut health, particularly by altering the gut microbiota, is exciting, with better gut health associated with benefits across many physical and mental health conditions. Despite this, it does not seem that increased consumer and scientific interest in gut health has yet resulted in substantial practice change. We wanted to understand this disparity between science, health professionals (specifically dietitians) and consumers.

As diet is recognised to substantially influence gut health, we conducted research focusing on dietitians’ perceptions of gut health. We hoped this would improve our understanding of how we can make sure research investigating relationships between diet, the microbiota and health provides outcomes that are useful to health professionals in practice.

Gut health and dietetics: now

Our conversations with dietitians revealed that this group consider gut health to include both gut symptoms and gut microbiome characteristics. Despite this, dietitians reported their main aim when working on gut health with clients is to improve symptoms, rather than goals specifically related to gut microbes. Current dietetic gut health management was reported to be strongly evidence based, personalised and multidisciplinary, with dietary recommendations primarily aligned with the Australian Dietary Guidelines.

Dietitians reported this strong emphasis on evidence-based practice limited their current engagement with gut microbiome specific practice, as dietitians reported diet-microbiome evidence can be difficult to keep up with and interpret, with limited translational outcomes. Importantly, dietitians recognised they could play an integral role in gut health research and health practice; however, they stressed the implementation of this would require specific evidence-based practice guidelines.

Importantly, these findings highlighted that diet-microbiome research that is focused on translational outcomes is essential to enabling dietetic practice relating to the gut microbiome. Whilst there is an abundance of publications aiming to find correlations between diet, the microbiome and health, often these do not use a nutrition professional in study design or analysis, and so translation is limited due to irrelevant or incomplete dietary data. It is essential that nutrition professionals are involved in this research area to ensure nutrition-related interventions are realistic, analysis is appropriate and findings can be applied in practice.

Consumers interviewed in this study reported they found scientific literature confusing and were unsure of the transparency or recentness of government dietary recommendations. Therefore, health professionals are an essential interface between science and client education, and so outcome-focused research that supports the development of practice guidelines is crucial.

Consumers reported turning to social media for health advice and education, especially as they could access seemingly more up-to-date recommendations in an engaging manner, including videos and graphics that explained how and why a dietary recommendation is made. Social media can be rife with misleading information; however, dietitians are well placed to stand above this noise and use social media as a tool to translate science-based dietary recommendations that consumers can trust, whilst advocating for health professionals as a voice of authority in this space.

Gut health and dietetics: the future

Until exact understandings of diet-microbiome interactions exist, dietitians reported that their practice in gut health would continue to focus on aligning clients’ diets with the Australian Dietary Guidelines.

Dietitians were aware that fibre-rich plant foods (eg, fruits, vegetables and wholegrains) are beneficial to the gut microbiome (known as prebiotic) and reported that recommendation of these foods is already routine due to existing well-recognised health benefits such as cardiovascular health. This approach to dietary management of gut health was different to what was reported by consumers.

Consumers considered diet to be highly influential in shaping their gut health; however, they attributed this mostly to fermented foods (eg, kombucha, kefir or sauerkraut) or probiotic-rich foods or supplements. This is not surprising as these foods are often marketed as being great for gut health and consumers had reported hearing of gut health mostly on social media or food advertising.

Although there is evidence that both probiotic-rich foods (foods that contain live bacteria) and prebiotic-rich foods (foods that feed the bacteria) may have gut microbiota specific benefits, precise recommendations regarding how often and how much needs to be consumed remain uncertain.

Prebiotic foods, however, are well known to be beneficial across a broad range of health conditions and are strongly encouraged in national dietary guidelines, as well as often being convenient, affordable and familiar options. Current adherence to dietary guidelines in Australia is extremely poor.

What do consumers think?

Consumers in this study considered gut health to be important to their ‘overall wellbeing’ and reported being motivated to make dietary changes to improve gut symptoms. This suggests that engaging with current consumer interest and encouraging diverse fibre-rich diets as a way to improve gut health may provide an opportunity to improve dietary guideline adherence and benefit a myriad of population health areas.

Health professionals are well placed to interpret and use science to improve client health. Whilst scientific evidence supporting how specific diets, foods and nutrients may influence gut health is still evolving, dietitians have an opportunity to engage with consumer interest in this space to support health based on what is known so far, and to advocate for their increasingly essential role as experts in diet-microbiome research and practice.

Professor Eleanor Beck and Professor Linda Tapsell contributed to the research referenced in the article.

^{Williams GM, Tapsell LC, Beck EJ. Dietitians' perspectives on the role of dietetics practice in 'gut health'. Nutr Diet. 2023;80(1):95-103. doi:10.1111/1747-0080.12778
Williams GM, Tapsell LC, Beck EJ. Gut health, the microbiome and dietary choices: An exploration of consumer perspectives. Nutr Diet. 2023;80(1):85-94. doi:10.1111/1747-0080.12769}

*Dr Georgina Williams is a postdoctoral researcher in diet and gastroenterology, working in the Centre for Research Excellence in Digestive Health. Her current research examines the role of the diet in gastrointestinal disease, with a focus on diet-microbiota interactions. Williams was awarded her PhD in 2022 from the University of Wollongong. This work explored the relationship between diet-microbiota interactions and metabolic health outcomes, including non-alcoholic fatty liver disease.

This research strengthened evidence pertaining to the role of dietary fibre, particularly from whole grains, in modulating the gut microbiome with potential for health benefits. A key finding of the work was the realisation of limitations in current diet-microbiota study design which has hindered research outcome translation, resulting in uncertainty in both consumer and dietitians. Williams completed a Bachelor of Nutrition and Dietetics at the University of Wollongong in 2017 and has worked as a dietitian across both public and private sectors.

Image credit: iStockphoto.com/DrAfter123