As we grow older, our digestive system undergoes various changes – gut muscles tend to weaken, whilst levels of good bacteria in the intestines decrease. This, combined with dietary and lifestyle changes, can leave us more susceptible to a number of digestive complaints.
However, there are plenty of small steps that can be taken in order to maintain good gut health. This week, we take a look at some of the factors responsible for a decline in gut health (below) – next week, some expert tips on maintaining digestive health in older age.
DIET AND EXERCISE:
As we get older, we tend to consume less dietary fibre – the indigestible carbohydrates found in plant foods such as fruit, vegetables and wheat. Dietary fibre aids digestion by helping to move food through the gut, absorbing water and thus softening stools.
When intake of dietary fibre is low, stools can become dry and hardened, making them much more difficult to pass – a condition commonly known as constipation.
Furthermore, exercise levels tend to decline with age. For a healthy gut, it is important to maintain a healthy weight – obesity is a known risk factor for a number of digestive conditions including heartburn and piles.
Ageing can affect our digestive system in a number of ways. Intestinal muscles can lose power (either naturally or as a side effect of medication), which can lead to constipation.
However, it is within the ‘gut flora’ – those trillions of bacteria resident in the intestines – that one of the most significant developments is seen. As we age, levels of beneficial bifidobacteria in the intestines tend to drop, whilst numbers of potentially detrimental bacteria such as clostridia and enterobacteria may increase, resulting in a less healthy balance.
And since the gut flora is an important part of our body’s natural defences – with the majority of the immune system located in the gut – this altered balance may contribute to the higher susceptibility of older people to infectious disease.
Antibiotics can also affect our gut flora. Antibiotics wipe out bacteria – and because such drugs cannot discriminate between ‘good’ and ‘bad’, they often destroy high numbers of beneficial gut bacteria, leaving us more vulnerable to infection.
This is why patients on a course of antibiotics can often develop diarrhoea – and since older people already have lower levels of beneficial gut bacteria, they are at increased risk. Clostridium difficile (C. difficile) is often responsible. This bacterium occurs naturally in the gut of around 4% of the population, but is normally kept in check by the beneficial bacteria there.
However, if these good bacteria are wiped out by antibiotics, the clostridia can multiply, producing toxins and causing diarrhoea. Given that older patients are ten times more likely to develop C. difficile-associated diarrhoea*, it is it is important to take steps to maintain good digestive health over time.
* Karlstrom et al, 1998