Treatment for chronic urinary tract infections may involve courses of antibiotics or antibacterials that can affect the bacterial levels in your gut.

What do gut bacteria or flora do?

The human gastrointestinal system contains about 39 trillion bacteria, according to the latest estimate, most of which reside in the large intestine. In the past 15 years researchers have established that many of these bacteria are essential for health. Gut bacteria help to:

  • properly digest food and protect from pathogens (harmful microorganisms)
  • detoxify harmful compounds
  • produce vitamins, such as B12 and K, and other nutrients
  • keep the gut healthy and balance the immune system

The bacteria in our gut microbiome come under three different categories:

Beneficial bacteria

These are the bacteria that have a positive effect on health, and these are the ones to increase with probiotic supplements, fermented foods and a quality diet. Examples of beneficial bacteria include Lactobacillus and Bifidobacteria.

Opportunistic bacteria

These can be harmful depending on their level. When they are in low levels (and when there is an optimum bacterial balance in the gut) they don’t cause harm to health. It is when these bacteria increase in numbers that they can start to affect the immune system, create inflammation and have a wide range of health effects. Examples of opportunistic bacteria include Klebsiella and Citrobacter.

Pathogenic bacteria

As the name suggests, these can cause a wide range of digestive health problems and also cause a wide range of symptoms throughout the body. Examples of pathogenic bacteria include Salmonella and Campylobacter, and these bacteria should ideally be eliminated through appropriate treatment.

How can the gut flora be disrupted?

A number of things that can disrupt the balance of gut bacteria or cause dysbiosis:

  • Stress
  • Antibiotics
  • Low soluble fibre diet (not enough fruits and vegetables)
  • High intake of carbohydrates and sugar rich foods
  • Poor digestion (low stomach acid, poor pancreatic output of enzymes, issues with bile secretion)

What are the symptoms of gut dysbiosis?

  • An increasing tendency to recurrent infections throughout the body
  • Development of systemic or vaginal candida (thrush)
  • Digestive symptoms including (but not limited to) gas, bloating, heartburn/GERD, constipation, diarrhoea, IBS (irritable bowel syndrome), SIBO (Small Intestinal Bowel Overgrowth) and IBD (Crohn’s and ulcerative colitis, among others)

Where are colonies of good bacteria found in the gut?

The small intestine is the crucial site of nutrient digestion and absorption. After leaving the stomach, food and bacteria move through this area fairly quickly, and so there are no huge colonies of flora (bacteria) in the small intestine. However, it is in the small intestine where we want a healthy recolonizing of beneficial bacteria, including lactobacillus and bifidobacterium species.

The large intestine is where the greatest number of bacterial colonies are located. Where the small intestine meets the large intestine is the location where absorption of fat-soluble vitamins takes place, along with the recycling of digestive enzymes. The goal of probiotic therapy is not only to properly populate the small intestine, but to repopulate the junction of the small and large intestine with healthful bacteria.

How can I support the good bacteria in my gut?

This can be broken down into four areas:





More information

The Effects of Probiotics, Prebiotics and Synbiotics on Human Health Markowiak, P., & Śliżewska, K. (2017). Effects of Probiotics, Prebiotics, and Synbiotics on Human Health. Nutrients, 9(9), 1021. doi:10.3390/nu9091021

Part 1: The Human Gut Microbiome in Health and Disease Bull, M. J., & Plummer, N. T. (2014). Part 1: The Human Gut Microbiome in Health and Disease. Integrative medicine (Encinitas, Calif.), 13(6), 17-22

Part 2: Treatments for Chronic Gastrointestinal Disease and Gut Dysbiosis Bull, M. J., & Plummer, N. T. (2014). Part 1: The Human Gut Microbiome in Health and Disease. Integrative medicine (Encinitas, Calif.), 13(6), 17-22