Prebiotics, probiotics, and kidney disease
Nancy Scanlan, DVM

What do probiotics have to do with kidney disease?

Kidney disease is one of the most common diseases in elderly dogs and cats. Recently it has been discovered that toxins created by certain bacteria can damage the intestinal wall. With enough damage, those toxins and bad bacteria enter the bloodstream and cause kidney damage. When kidneys can’t filter out those toxins because they are damaged, even more harm is done to both the kidneys and the intestines. As time goes on, there may be excessive numbers of bacteria in the intestines (dysbiosis), or types of bacteria may change to increasingly harmful ones, or both things may go on at the same time. Bacterial populations may move to different places in the intestinal tract, causing high numbers of bacteria in the wrong place. Breakdown products of proteins are the ones that cause the most harm. This is one reason a lower protein diet can be helpful for kidney patients.

This cycle can be started by kidney disease itself, or it can be started by intestinal problems such as chronic diarrhea or Inflammatory Bowel Disease. It can even be caused by severe liver disease, with toxins causing intestinal disease which then affects the kidneys. Prolonged use of antibiotics can decrease the numbers of beneficial bacteria, or cause an overgrowth of resistant, bad bacteria. Good bacteria (probiotics), taken by mouth, can re-establish a bigger colony of beneficial bacteria and give competition to the bad bacteria. Prebiotics (various types of fiber) can increase the growth of beneficial bacteria. In addition, some types of prebiotics can stick to toxins and prevent them from damaging the intestine or from being absorbed.

What does that mean for an older animal? If they don’t have kidney disease yet, but are having problems with chronic diarrhea, prebiotics and probiotics can help bring it under control. If they are at the stage of dysbiosis, with massive numbers of bad bacteria living in the wrong place in the intestine, it might be necessary to give antibiotics to get them under control before healthy bacteria like lactobacillus can get a foothold and continue to multiply. But antibiotics kill all bacteria. So it is best to wait 2 hours after the antibiotic is given before giving a probiotic. In this case it is even more important to give the probiotics at the correct time every day. Or you can use a beneficial yeast, such as saccharomyces, which is not affected by antibiotics.

Often adding a prebiotic will help greatly in this process. Prebiotics are fibers, which range from highly soluble (forming a gel) to highly insoluble (fibers that do not break down) and everything in between. Fibers that work well for one animal can be a complete disaster for another one. Canned pumpkin, beet pulp, and apple pectin are the 3 prebiotics I have found most useful. You only need a little bit. Start with the pumpkin first (even cats will eat it, but don’t use large amounts for them). If that makes things worse, stop and try the pectin. If it fixes everything, only use the pumpkin. If it helps a little, try adding the pectin. The reason you can’t predict what will work is because the population of bacteria is different for different animals.

If your companion already has kidney disease, this treatment can help also, even if they do not have diarrhea. It will help decrease the toxins being created in the intestines, and help prevent damage to the intestine. Some research has shown a decrease in lab values of Blood Urea Nitrogen (BUN) in humans with kidney disease when taking probiotics.

Investigations have been conducted in humans to see how various probiotics and prebiotics change the bacteria and environment in the intestines. To see research papers about these investigations, subscribe to HOPE, our newsletter with integrative holistic medicine news and updates. And a few cute pictures.