Do We Really Need to Avoid Bifidobacterium on SCD?

Do We Really Need to Avoid Bifidobacterium on SCD? (Updated September, 30 2026)

I first wrote this article in 2022 and updated it again in 2024. I have continued researching Bifidobacterium because I feel strongly that it is something we should keep talking about in the SCD community.

For a long time, the advice has simply been not to include Bifidus. I understand where that recommendation came from, but I don’t think we should stop there. I want to know why something is excluded, what the research actually showed, and whether newer research supports the same conclusion.

I am not suggesting that everyone should start using Bifidobacterium. My goal is to give people the information so they can look at the research, talk with their medical providers, and make their own informed decision.

There has been enough new research since I first wrote this that I felt it was time to update it again.

What Is Bifidobacterium?

Bifidobacterium belongs to the lactic acid bacteria group and lives naturally in the intestines.

It may be listed under several names including B. bifidum, B. breve, B. infantis, B. lactis, B. longum, Bifido, Bifidus, Bifidus Brevis, Bifidus Infantis, Bifidus Longum, and others.

It is generally considered one of the beneficial bacteria found in a healthy gut microbiome.

Why Is Bifidobacterium Avoided on SCD?

Bifidobacterium is mentioned in Breaking the Vicious Cycle as a bacterium to avoid when making yogurt, and Elaine Gottschall also discussed avoiding it more broadly.

One of the concerns came from a 1995 study looking at intestinal bacteria in populations with different risks for colon cancer. The researchers found that Bifidobacterium longum and Bifidobacterium angulatum were more common in groups considered at higher risk for colon cancer.

The study showed an association. It did not show that Bifidobacterium caused colon cancer.

That distinction was already something I questioned in my original article. Were higher levels of Bifidobacterium contributing to disease, or were they a result of changes already happening in the gut?

We did not have an answer.

When I updated the article in 2024, I was able to find an old conversation involving Elaine that gave more context to her thinking.

A University of Wisconsin professor had described Bifidobacterium bifidum as a “friendly” bacterium and discussed the relationship between Bifidobacterium and Bacteroides in the colon.

Elaine did not completely dismiss the possibility that Bifidobacterium could be beneficial. She questioned whether the research was strong enough and went back to the 1995 colon cancer study as part of her reason for remaining cautious.

Read the old discussion involving Elaine and Bifidus

I do not include this to criticize Elaine. I have said before that I think she would have continued following the research if she had access to what we know now.

My 1999 edition of Breaking the Vicious Cycle also did not make the Bifidus restriction as clear as it later became in the online SCD community. I used a commercial starter containing Bifidus for years before I even knew it was considered off-limits.

That was one of the reasons I eventually started looking more closely at the recommendation.

Does Bifidobacterium Increase the Risk for Colon Cancer?

The research since 1995 has not shown that Bifidobacterium causes colon cancer.

When I updated this article in 2024, I included a 2020 review discussing research where certain Bifidobacterium strains showed anti-inflammatory and anti-tumor effects in laboratory and animal models. That certainly did not fit with the idea that Bifidobacterium should simply be viewed as a cancer-promoting bacterium.

Now there is newer research to consider.

In September 2026, Mayo Clinic published findings from its Cancer Microbiome cohort. Researchers analyzed stool samples from 1,364 cancer patients across different types of cancer, stages, and treatments.

Mayo Clinic reported:

“Researchers also identified specific gut bacteria associated with survival in colorectal, liver and intrahepatic bile duct, melanoma, ovarian and prostate cancers. In liver and intrahepatic bile duct cancer, Bifidobacterium longum was associated with longer survival and Blautia A massiliensis with shorter survival.”

This does not mean taking Bifidobacterium will improve cancer survival. The study found an association, not cause and effect.

But I think it is important to put this beside the research that originally raised concern about Bifidobacterium on SCD.

• The 1995 study found certain Bifidobacterium species associated with groups considered at higher risk for colon cancer.
• That association became part of the reason Bifidobacterium was avoided on SCD.
• Newer research has not shown that Bifidobacterium causes colon cancer.
• The 2026 Mayo Clinic study found B. longum associated with longer survival in people with liver and intrahepatic bile duct cancer.

None of this makes Bifidobacterium a cancer treatment.

It does make the original cancer concern much less convincing as a reason for permanently excluding it.

Read the Mayo Clinic report

Does Bifidobacterium Exacerbate IBD?

This was another question in my original article.

Bifidobacterium is commonly reduced in people with IBD, and research has continued looking at whether restoring it could have benefits. But that does not mean simply adding Bifidobacterium is going to treat Crohn’s disease.

A newer study gives us a good example.

In 2025, researchers published a randomized, double-blind, placebo-controlled trial looking at Bifidobacterium breve Bif195 in 33 people with small-intestinal Crohn’s disease. Participants received either Bif195 or a placebo for eight weeks.

The study found:

• Bif195 did not significantly improve bowel wall thickness compared with placebo.
• It did not significantly improve symptoms, quality of life, fecal calprotectin, or the other clinical outcomes researchers measured.
• B. breve increased in the treatment group, but the increase was not statistically significant after adjustment.
• Researchers found differences in participants’ microbiomes before treatment that may have influenced how they responded.

I think that last point is especially interesting because it reinforces something I have believed for a long time: one size does not fit all.

The study does not give us a reason to use Bifidobacterium as a treatment for Crohn’s disease. It also does not show that Bifidobacterium made Crohn’s worse. No serious adverse events were reported, and adverse events were not more common in the Bif195 group.

That leaves us with a much less dramatic answer than either “Bifidobacterium treats Crohn’s” or “people with Crohn’s should never have Bifidobacterium.”

The research is still developing.

Read the 2025 Bifidobacterium breve Crohn’s study

What About Bifidobacterium and Butyrate?

I also want to correct something from my original article.

I cited a study that described Bifidobacteria as “the main source of butyrate production.” The current understanding is more specific than that.

Bifidobacterium is not one of the main bacteria that directly produces butyrate. It can, however, support butyrate-producing bacteria by breaking down carbohydrates into compounds those bacteria can use.

So Bifidobacterium can be part of the process, but adding it does not automatically mean you are increasing butyrate production.

Who Should Be Cautious or Avoid Bifidobacterium?

Most people are not going to fall into these categories, but there are situations where adding any probiotic, including Bifidobacterium, should be discussed with your medical team first.

Situations where the risk may be higher include:

• Severe immune suppression — including some people undergoing chemotherapy, organ transplant recipients, or people with conditions that significantly suppress immune function.
• Central venous catheters (CVCs) — there have been documented cases of probiotic organisms causing bloodstream infections involving central lines.
• Short bowel syndrome — especially worth discussing for people who have had significant intestinal surgery.
• Severe acute pancreatitis
• Severe active IBD
• Active sepsis or another serious systemic infection

There are also situations where I would have a conversation with your provider rather than automatically avoiding Bifidobacterium. These include pregnancy, breastfeeding, a history of strictures or fistulas, recent hospitalization, and current use of immunosuppressive medication for IBD.

This does not mean Bifidobacterium is unsafe for everyone in these groups. It means individual medical history needs to be considered.

Why I Still Use a Yogurt Starter That Contains Bifidobacterium

My purpose in this article is to share what I have found through my continued research, not to tell anyone else what they should do.

For me, I decided years ago that I was comfortable using a yogurt starter containing Bifidobacterium.

Part of that decision came from realizing I had already used it for years before I even knew the SCD community considered Bifidus off-limits. My experience with it had never been negative.

I also continue to make and encourage 24-hour SCD yogurt. It has been a big part of SCD since the beginning, and it remains a big part of my own diet. The starter I use contains Bifidus.

As I have continued looking at the research, I have not found a reason that changes my decision for myself.

The original cancer concern was based on an association that did not prove Bifidobacterium caused cancer. Newer research has not supported that causal connection. Bifidobacterium is normally found in a healthy microbiome, and although the research does not show that adding it will treat Crohn’s disease, I also don’t see evidence supporting a blanket rule that everyone with Crohn’s should avoid it.

That is my conclusion for my own situation.

You don’t have to make the same decision. I’m not here to influence what you do, just to provide information and context that I think is imiportant.

This is really what I want people to take away from this update. I don’t want the discussion to stop at, “Bifidus is not allowed.”

I would rather people ask why.

Look at the original research. Look at what has been published since then. Consider your own health history and where you are with your disease. Then talk with your medical providers and make an informed decision.

I will continue following the research because I am sure we have not heard the last word on Bifidobacterium and the microbiome.

A Final Reminder

This article is for informational purposes only and is not medical advice.

Do not discontinue medication or change your prescribed treatment because of something you read here. Talk with your doctor, gastroenterologist, dietitian, or other qualified healthcare provider about changes that may affect your treatment.

If you decide to make dietary changes, go slowly.

Changing several things at once can make it difficult to know what helped, what did not, or what caused a reaction. Adding one thing at a time gives you a better chance of seeing how your own body responds.

My goal is not to replace one rigid rule with another. I want people to understand where the recommendation came from, consider the research we have now, and make an informed decision from there.

This article was originally published September 27, 2022, updated January 23, 2024, and updated again September 30, 2026.