In PREDICT, we initially discovered positive health associations for 15 ‘good bacteria'. We have since expanded this list to 50 ‘good bacteria'.

These bacteria are associated with strong metabolism, lower blood pressure, and better blood sugar control. People with these bacteria tend to have fewer signs of dietary inflammation, lower levels of triglycerides and bad cholesterol, and less abdominal fat mass. These bacteria are also associated with better fat sources which are high in polyunsaturated fatty acids such as omega-6.

We have also now identified 50 ‘bad bacteria’, which have been associated with the opposite effects.

These bacteria are linked with a higher risk of dietary inflammation, higher blood pressure, and poorer glycemic responses. For people with these bacteria, we see more dietary inflammation, higher levels of triglycerides and bad cholesterol, and greater abdominal fat mass. These bacteria are also associated with poorer fat sources which are low in polyunsaturated fatty acids such as omega-3 and 6.

New research has allowed us to identify four key health-related groups, or 'clusters,' of gut bacteria. Each cluster contains a unique mix of beneficial and harmful bacteria. Some bacteria may even show up in multiple clusters if they affect different areas of your health.

This microbial cluster is associated with GlycA, a biomarker of chronic low-grade inflammation in the body. People with higher levels of good bacteria and lower levels of the bad bacteria in this cluster tend to show lower systemic inflammation. Low grade systemic inflammation has been linked to worse health outcomes in many clinical trials.

These bacteria are linked to markers of glucose regulation and insulin production, including HbA1c, fasting glucose, and C-peptide. The presence of higher levels of good bacteria and lower levels of bad bacteria is more common in people with better glycemic control, and they may contribute to healthier metabolism, insulin sensitivity, and better metabolic health outcomes.

This group of gut bacteria is associated with key blood lipid markers such as HDL (good cholesterol), total cholesterol (combined good and bad cholesterol), triglycerides, and lipoprotein particle size (smaller particles can more easily slip into blood vessel walls and are more likely to cause plaque buildup). Higher levels of good bacteria and lower levels of bad bacteria tend to appear in individuals with a more favourable lipid profile, suggesting that the microbiome may play a role in cholesterol transport, fat metabolism, and contribute to overall heart health.

This cluster of bacteria is associated with markers of unhealthy fat accumulation, particularly visceral fat (fat stored around the organs) and liver fat. These types of fat are more strongly linked to metabolic dysfunction, in comparison to fats stored in other places. A higher presence of good bacteria and lower presence of the bad bacteria in this cluster may reflect a microbiome profile connected to better heart and metabolic health.