Gut microbiome, antibiotics and older people

There has been a massive swing to the proactive, early use of high dose antibiotics in those people attending accident and emergency departments in the UK with suspected infection; specifically, something we call ‘sepsis’ – this is a condition where we are at risk of being overwhelmed by infection, usually by bacteria although other organisms can cause this.

Warning signs are raised temperature, dropping blood pressure, high breathing rate, drowsiness.

In an attempt to treat early – something that has been shown to reduce the numbers of people dying from infection (that is, treatment within the first three hours of arriving in hospital or seeing a doctor or paramedic), the Sepsis Bundle has been created and rolled-out across the country.

This bundle, which is in effect a list of instructions to follow when sepsis is suspected has improved compliance with guidelines, early treatment with antibiotics and other measures to support people and, hopefully, has reduced the numbers of people either dying or becoming critically ill.

This is all very good.

There is another side to this… It relates in some ways to the models of care I described in the last blog – the medical, older people and palliative models – the medical, being treat and investigate at all costs, and, for older people, aid recovery and care, and, the palliative, which is care, support and ensure that the person’s subjective experience is given priority.

When an older person attends A&E, the most common cause in our society, being, a fall at home; the receiving doctor or nurse has a dilemma – they need to find-out if the person is OK – do they need urgent treatment? Oxygen, intravenous fluids, antibiotics, or, can the team move on to the next phase and try to determine why they have fallen – was it a stumble relating to reduced muscle strength in an older person with arthritis, did they lose consciousness, are they harbouring an infection?

And, it is to the last of these that the system often defaults, with an older person who has fallen, becoming an older person who has a urine infection.

The science, or rather the practice of treating urine infections in older people can be patchy.

For this, I have (my own, non-evidence based) rule of thirds; one third of people you suspect to have a urine infection have one, one third of the time the antibiotics use to treat the urine infection, if present, are ineffective as the bacteria are resistant and one third of the time the antibiotics you use work.

This is not very scientific, but some people appreciate rules of thumb.

There is an empirical method for determining the presence of urine infections – examining a sample of urine under the microscope. If bacteria are present or there are signs of bacteria present, then the likelihood of infection increases; it is only after those bacteria have been grown in a lab and tested against different antibiotics, which often take 48 to 72 hours, do we know if there is definitely and infection and what treatment to give.

I have talked previously about asymptomatic bacteruria (& Bear Grylls) – my point here is the frequent use of antibiotics in situations where the evidence for bacterial infections is small.

In older people these are falls and confusion (delirium).

The usual philosophy with respect to the use of antibiotics is that they might work, they don’t do much harm and we need to do something.

It is this thinking that has resulted in the many cases of Clostridium difficile we see reported nationally – this is, where toxic gut bacteria are allowed to flourish because the normal balance of beneficial bacteria is affected by the use of antibiotics.

Clostridium difficile diarrhoea is a horrendous condition which can make people very ill, necessitate their isolation and can become chronic – being a risk every time they subsequently take antibiotics.

I am less concerned here about Clostridium difficile, but instead the unfathomed gut microbiome that exists within all of us. The unimaginably complex density of bacteria that control many aspects of our health and wellbeing – supporting digestion and metabolism, the control of hormone levels, function of the liver, and even, potentially our response to stress and levels of neurotransmitters.

We, the homeostatic organisms that have evolved over the past four billion years, exist in a state of serenity when well, but things can be thrown out of kilter by disease.

Separately, we know that the numbers of antibiotic resistant bacteria are increasing globally – this is another issue.

What I wonder is whether there is harm in using antibiotics?

Like all aspects of medicine, particularly in relation to treatment, there is always a balance, between harms and benefits – if the treatment I offer kills the bacteria or cancer but also kills the person I am treating, I haven’t done a good job.

What if the treatment I give is wrong and potentially harms?

This is my question relating to the third of the third of the third (or some other numerical mixture of facts and figures) – what happens when we treat an older person with antibiotics when they either don’t have an infection or the bacteria present are not causing any harm (and might even be helping us)

I don’t want to knock my fellow Scotsman, Fleming – his discovery of penicillin has resulted in unimaginable benefits to the entire human race. What, however have the harms been?

The explicit harms are easier to determine – they are, Clostridium difficile, MRSA, ESBL, MDRTB, and a host of other acronyms and Latin phrases.

My message, or perhaps my question is whether enough thought is given towards the use of antibiotics every time they are used or prescribed; enough thought about the benefits and the potential harms. In the UK we are relatively protected from the abuse of antibiotics, in many countries, antibiotics are unregulated and sold directly.

What is the good we are doing and what is the harm? Do not consider everything we don’t understand to be caused by bacteria – sure, bacteria are out there, in numbers we cannot imagine, yet, only a few are harmful and only a few are the cause of harm – for, there are other dangers which are not always related – pain, fear, anxiety, depression, isolation and loneliness, lack of physical fitness, poor diet, right-wing politics, and so on.

Antibiotics are great and I am an advocate, but, before using them think homeostasis, think cause and effect and consider evolution.