Explains the impact of the gut microbiome on health

Does eating dairy influence mental well being?

The Gut and Mental Well Being

We have known for a long time that individuals who eat a great diet, and exercise regularly,  tend to manage stress and anxiety much better than others. Certain foods are associated with cognitive performance e.g. oily fish, nuts and seeds, because of the omega 3 oils they contain. But what about other foods e.g. dairy? And how might they influence how we feel?   And is this related to the connection between the gut and the brain?

The Bi-Directional Nature of the Gut-Brain Axis

The gut and the brain communicate with each other all the time. the relationship is bi-directional ie the brain talks to the gut and the gut talks to the brain. Just like two people, anyone can initiate the conversations.  In the past a lot of research has focused on how the brain might influence feelings of fulness or satiety.  What communication mechanisms exist to relay to the brain that I have eaten?  What might happen in terms of neurotransmitter production – chemical messengers – which  tell me to stop eating. Interestingly, these neurotransmitters are produced not only in the brain and nervous system, but also in the gut.

The Helpful Bacteria

The focus is shifting towards how the microbiome i.e. the bacteria living in the gut, might affect the production of these neurotransmitters. Does the type of bacteria living in the gut influence what neurotransmitters are produced, and so influence the activity in the brain, our decision making, and our ability to manage anxiety.

Current research suggests two types of bacteria are considered particularly beneficial to both the gut and the brain – Bifidobacteria  and Lactobacillus. High levels of stress seem to reduce the concentration of lactobacillus in the gut. Can these bacteria affect mental health and the gut microbiome?

The Gut-Microbiome and Anxiety

Dr Kathrin Cohen Kadosh describes how fine-tuning of the gut-brain axis occurs during the second decade of life. The second decade is a time of enormous change, we start secondary school,   we go through adolescence and puberty, we are especially vulnerable to peer pressure.  Socially, we search for our tribe. This decade is also where 2/3rds of mental health problems are considered to start – problems which we often carry with us through life.

The Dairy Study

Dr Cohen-Kadosh described a comprehensive study which looked to psychological profiling, nutritional markers, stool sampling, and brain imaging, and a targeted dietary intervention . The idea was to look for changes in neurotransmitter production.  The study population was divided into two groups – those classed as of low anxiety traits and those with high anxiety traits.  For the scientists among you,  the study was a randomised control trial, and the intervention was the provision of a dairy derived prebiotic: galacto-oligosaccharide. Prebiotics are those foods which contain nourishment for the good bacteria in the gut. Most prebiotics are plant based with just the one dairy derived  galacto-oligosaccharide identified.

Following the dietary intervention,  those individuals who were considered of high anxiety traits presented with less anxiety than before the intervention, and also suggested an improvement in positive decision making. Those individuals who were already of low anxiety traits did not show any difference in outcomes.

Dairy and Mental Health

As an industry focused webinar* the idea is to look to and develop supplements of various kinds to improve mental wellbeing. But I thought about how during that 10 – 20 year age band there is a tremendous turn down in dairy intake, nor does green vegetable intake (another source of prebiotics) tend to meet recommended guidelines.   Children, from the age of 5 tend to reduce their intake of dairy products. Could this be a way forward in helping us all to improve our  mental health generally? Children and adolescents have an increased need for dairy servings but worries about weight gain, and turning to sugar free fizzy drinks rather than milk as a drink, affects overall intake.

Perhaps supporting children and adults to maintain a good intake of dairy not just because we are aware it’s good for our bones, but also because it may help us manage anxiety and stress is worth considering. Consuming dairy may increase the helpful Bifidobacteria and Lactobacillus colonies affecting the gut microbiome and  mental health.

What is a serving of dairy?

See below for suggested servings – aim for ≥3 servings per day to meet your needs, with live yogurt being considered especially beneficial to gut health.

  • 120-150ml yogurt – plain low fat or Greek preferred versus fruit flavoured which may contain added sugar or sweeteners
  • 28g cheese
  • 200ml milk

Enjoy! If you need help with your diet or lifestyle, and would like to work on gut nutrition, please get in touch.

2020 and Covid

This was my introduction back in 202 when I originally wrote this blog.

This year, I think we have all struggled somewhat with personal challenges to our mental well being. We have been affected by stress about the health and safety of family members, and our children’s education. We have not been able to socially connect in the way we might normally, and also had to perhaps deal with financial upset. Anxiety and worries leading to poor sleep habits further affects our ability to achieve and maintain a level of calm.  Covid-19 feels like  the never-ending story of 2020.  On  V-Day, I shed a tear listening to the story of 90 year old Margaret Keenan and her confidence in being the first, non-trial person,  to be vaccinated against Covid-19.  Coming up to Christmas, it really does feel like 2021 will be a better year, for all of us.

The Gut and Mental Well Being

It seemed pertinent that I was then scheduled to watch a webinar on mental health and the gut microbiome.  The webinar was industry focused. Discussion centred  on functional foods and what we, as consumers are looking for in foods that might  improve mental wellbeing. What is incredibly positive, is that none of us seems shy any longer, to let others know when we are struggling with things. It’s almost like Covid-19 and 2020 has somehow given us all permission to say out loud: ‘I am finding life difficult at the moment’. ‘I am not really coping’. Personally,  I have felt like I am on a roller-coaster of emotions at times – sometimes coping admirably, and sometimes not. So to learn from the webinar, that dairy,  in the context of an evidence based trial,  might impact my ability to cope with anxiety was really interesting.

* this comments refer to a webinar on ‘the influence of diary on the gut microbiome’ from 2020


Felicity Lyons

Hi there! My name is Felicity. I am a registered dietitian and sports nutritionist with a proactive approach to healthy living. My job is to interpret the complexity of nutrition science and translate it into messages and guidance that you can understand. Healthy Living? It's easier than you think!