2. Enzyme Supplements
Instead of missing good bacteria, you good be lacking certain important enzymes. The enzymes lactase and amylase, for example, break down dairy and complex carbohydrates respectively. Once these foods are broken down, they can then be taken up in the body as nutrients, with whatever not being needed to be discarded as waste.
When foods cannot be broken down, they simply languish in the gut, where they have every opportunity to ferment. Fermentation often results in sugar and its byproducts. If these are not used by the body thanks to activity, they are ultimately stored as fat.
Enzymes are produced naturally by the body but as with all bodily functions, this is affected by age. From about the age of 40 onwards, the body starts producing less and less of this important digestive tool. If you are older and suffering from bloating, you may specifically be lacking important enzymes.