Trillions of bugs that inhabit our guts are with us throughout our lives and they don’t just sit around and do nothing; they influence our health, moods, our ability to digest certain foods and even our susceptibility to disease. More and more research is being done that looks into how our guts look like at different stages in our lives. Although we are far from understanding it all, the key findings are that early childhood is where big changes in our gut bacteria composition occur, and that after childhood our gut bugs are pretty stable throughout our lives. Here’s a glimpse of how our guts look at different life stages and what we could do to make our gut companions and, eventually, us happier.
Birth and Infancy
The way we are born, vaginal or C-section, has a big impact on our gut composition and health not only during childhood but also later in life. For instance, children born vaginally get bacteria found in the mother’s birth canal and faeces and therefore the gut bacteria of mothers and babies born this way are more similar. However, children born through C-section get more bacteria found on the skin of their mothers, doctors or nurses and so in the early days these children have less similar gut bacteria to their mothers . Some studies found that children born through a C-section have a higher risk of allergies or a higher risk of obesity later in life , . While these are important results, it is important to bear in mind that these findings are just associations and not direct causal relationships and there is plenty you can do to support gut health throughout early life.
Breastfeeding plays an important role in the developing gut of babies because it gives them lots of good gut nutrients and prebiotics from the mother, strengthens the immune system and helps create that special bond between mother and child. At this stage, the bacteria in babies’ guts are more of Bifidobacteria type which is specialised in breaking down the sugars found in mothers’ milk. There are now some great formula formulations, which try to mimic the prebiotic element of breastmilk. However, with the introduction of solid foods in babies’ diets, the diversity of gut bacteria escalates and gradually starts resembling that of an adult . At this stage, it is important to slowly introduce gut-loving foods, including a variety of different plant-based foods and like fibre-rich ones that would boost the diversity of the gut bacteria and eventually the health of the child.
Antibiotics prescription is a common way to treat childhood bacterial infections. However, they may disrupt gut bugs long-term. If they are unavoidable, some ways in which we can restore the gut community after an antibiotics course could be through probiotics supplementation (specific probiotics have been formulated for use after antibiotics) or through probiotic foods, such as yoghurts or kefir or fibre-rich foods.
At this stage, teenagers tend to become more aware of their appearance and how they are perceived by others. This often leads to stress or anxiety which, interestingly, can affect their gut bacteria too through the gut-brain axis. Indeed, a lot of research suggests that our moods affect our gut bugs or vice-versa through the chemicals these bugs send/receive to/from the brain. As diet is a major contributor to how our gut looks like, one way we might be able to slow down these anxiety bursts at teenage years would be to make slow improvements to our diets by adding more fibre and plant-based diversity. Of course, at this stage hardly any teenager would say a big YES, PLEASE to a bowl of beans and salad. But when we are starting to realise that fibre-rich foods not only influence our moods but our appearance too , maybe that bowl of beans is not that bad after all. Making some simple swaps can help teenagers increase their fibre gradually.
Think early twenties: student life, living away from home, sleepless nights, parties or ready meals at odd times. While these are fond and great memories that last a lifetime, forming a long-term habit out of these at this stage in life may not be the kindest way to treat our gut companions. Although the gut bacteria are generally stable at this time, they can still undergo changes depending on what we eat. For instance, switching to a heavy meat-based processed food diet leads to the loss of bacteria that can deal with those important plant-based fibres . Processed foods have the ability to trick our brains into believing we still need plenty more food when we actually are full, and so we end up eating more!  Home cooking can help us take back control of how much and what we eat and is often cheaper.
Our gut bugs are also tuned to day-night cycles and so the night bugs are usually dealing with body repair while we are sleeping. Eating or drinking during the night or having lots of late nights can mess up this perfect orchestration and affect our moods and especially our body weight control mechanisms .
Pregnancy comes with lots of changes in women’s bodies which ultimately may impact the health of the future mother and baby. These include having more of gut bacteria Firmicutes which are often seen in obesity and/or more chemicals associated with stress and inflammation. While these changes are generally normal in pregnancy as they prepare the woman for giving birth and nurturing the baby, too much of these is not great because of the potential risks of gestational diabetes or a child’s growth problems . Antibiotic use during pregnancy may also affect the baby’s gut health or immune system but there is plenty that can be done to support gut health throughout pregnancy. Pregnancy results in changes to digestion, namely, things tend to slow down to maximise nutrient absorption from food. This can ultimately result in constipation, which as well as being uncomfortable can also disrupt the balance of bacteria in your gut. Consuming enough fibre and water and keeping active can help ease constipation – all great ways to have a happy mind and gut. The mother, the baby and let’s not forget those trillions of gut bugs will be so grateful for these tiny changes in daily routine
Menopause is another stage in women’s lives where their bodies go through major transformations. Generally, there is little information on how the gut bacteria look like and what they do at this stage in life. A study showed that giving probiotics to postmenopausal women led to improved bone health . Another showed that short-term intake of soy-isoflavonoids (oestrogen-like molecules) by postmenopausal women helped decrease gut bacteria numbers that promote inflammation and are more common in obese postmenopausal women . Your gut bacteria play an important role in how your body breaks down and gets rid of oestrogen too, so if something is out of balance here, it may influence menopausal symptoms.
As people age, the risks of old age conditions, like heart disease, mobility problems or dementia and the increased use of medication go up. Together with these, the gut bacteria change as well, becoming less diverse and possibly losing many important functions we are now beginning to learn. Let’s not forget that if older people find it difficult chewing, have mobility restrictions preventing them from cooking their own food or aren’t motivated to cook alone, these may reduce the quality of their food, including those of a plant-based nature and fibrous foods, which in turn has an effect on gut bacteria. In addition, as we age, our ability to produce bile decreases . Bile is important to emulsify fats for digestion and absorption and plays a crucial role in the balance of the bacteria in our guts. If our fats aren’t properly broken down, this can have a negative impact on the bacteria in our gut .
Of course, this is not the case with all older people. For instance, those who live close to 100 or beyond seem to have gut bacteria more similar to those of younger people, and less similar to those of people in their late 70s or 80s . What is special about these people is that their diets are rich in fibre, poor in animal fats and they benefited from increased physical activity. This healthy lifestyle was probably maintained throughout their entire lives. The more interesting thing is that those who live in care homes had a less diverse gut bacteria and worse mental and general health than those who were living in a community surrounded by friends and family . Maybe living in a nurturing community would be the answer to good gut and long healthy life?
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