We use phrases such as “follow your gut” or “listen to your gut” quite often when we have to make crucial decisions. Have you felt “butterflies in your stomach” or “a numbing feeling in your stomach” when you are anxious? Well, you are likely getting signals from an unexpected source: your second brain — the gut. Gut health can directly influence the expression and management of our mental health including depression, anxiety and stress.
The gut microbiome is the community of microbes and their genes that reside within the gastrointestinal tract and are a key driver of neurobiological and behavioural development.
Research on the human microbiome clearly links dynamics in the gut with neurobiological development in children.
Dysbiosis (increase in unhealthy bacteria in the gut) affects infant and toddler behaviour such as feeling scared or fearful, feeling depressed or disconnected, irritability and anxiety/ nervousness and cognitive development such as learning, speech, concentration and analytical thinking.
Evidence from human studies of autism spectrum disorder suggests that the microbiome continues to play an active role in behavioural and cognitive development.
The connection between the gut microbiome and subclinical behavioural changes is clearly important as normal behaviour and behavioural disruptions develop in childhood and this period of development offers opportunities to intervene and treat many mental health or behavioural disorders as they emerge.
The microbiome in children communicates with the central nervous system to influence social, academic and cognitive behaviour through several pathways that include neuroendocrine and immune system coordination, vagal nerve stimulation and neurotransmitters.
Let us have a look at the various mechanism of gut health that influence children’s mental and behavioural health:
Like the brain, the lining of the gut is full of nerves called the enteric nervous system, or ENS, also referred to as the “second brain”. The enteric nervous system has similar neurons and neurotransmitters as found in your central nervous system. ENS lines your entire digestive system with more than 100 million nerve cells forming two layers. It runs from the oesophagus to the rectum.
This connection between the brain and gut affects your digestion, mood and the way you think. The ENS secretes chemicals like dopamine, serotonin, and gamma-aminobutyric acid. All of these are mood-regulating chemicals. Healthy gut microbiome works as a shield from anxiety and depression among children to a certain extent. Diet can help your bacteria protect your mental wellbeing because eating the right foods feeds the happy bacteria. When there are plenty of different healthy bacteria, your microbiome is more diverse and produces substances which increase mood-lifting chemicals, like dopamine, serotonin and GABA.
The bidirectional communication between the central nervous system and gut microbiota, is referred to as the gut-brain-axis and is linked to several mental illnesses including anxiety and depression that are becoming common in children today.
A normal or vaginal delivery exposes a newborn to a diverse range of microorganisms, whereas, babies delivered through C- section get a partly different and less diverse microbiome. Children born through normal delivery are likely to have better mental health.
Breastfeeding infants contributes to good gut health to a great extent. Breast-fed infants have a more enriched and diverse microbiome as compared to formula-fed children. Human milk oligosaccharides, the powerful pre-biotic which an infant gets through breast milk influences gut health and mental health of infants throughout childhood. Exclusive breastfeeding of infants till six months ensures gut biodiversity and allows infants to develop into children with lesser instances of depression, anxiety, anger and learning disabilities.
The diversity of microorganisms continues to grow as and when solid foods are introduced and also with environmental exposure (mud, play, etc.). The introduction of a variety of solid foods impacts the range of microorganisms in the gut. A diet rich in diverse food groups such as vegetables, whole grains, fermented foods, fruits, pulses give rise to healthy bacteria. Whereas, a diet rich in sugar-sweetened beverages, processed food, artificial sweeteners and junk foods gives rise to bad bacteria.
Excess cleanliness and sanitation practices may compromise the microbiome. Exposure to natural flora through mud play, floor play, etc. can help in building up the gut bacteria beautifully. The friendly bacteria present in mud helps the brain to release a happy hormone. Not just this, it boosts the immune system and promotes the development of the child in every manner. Next time whenever you try to become extra cautious with the cleanliness of your child, just remember you may compromise their gut microbiome and cognitive health.
Lifestyle has a great impact on gut flora. An active lifestyle from childhood can ensure good bugs. However, a sedentary child will have poor gut health. A sedentary lifestyle and mindless eating are the major causes of obesity among kids, which make them dull and anxious over a period of time. Obesity also alters gut health leading to poor mental health.
It is important for your little one to have plenty of good bacteria and healthy gut microbiome as they grow to ensure they develop as both physically and mentally healthy individuals!
Manjari Chandra is a consultant, functional nutrition and nutritional medicine, Manjari Wellness, New Delhi. Her column appears every fortnight