The Cedars Sinai Diet, also know as The Low Fermentation Diet, was originally developed by Dr Mark Pimentel of Cedars Sinai Hospital in LA. The diet used to manage symptoms of small intestinal bacterial overgrowth (SIBO).
In this article I am going to outline the low fermentation diet and how it works to reduce SIBO symptoms. I am also going to give you my opinion and explain what I advise clients with SIBO.
Table of Contents
What is SIBO?
SIBO stands for small intestinal bacterial overgrowth and occurs when an individual has a higher than normal level of bacteria living in the small intestine.
You can find out more about SIBO in my other article here.
What is the low fermentation diet?
The low fermentation diet has been designed to reduce symptoms of SIBO through changes in meal timings and avoidance of fermentable foods.
Foods which are low in fermentable carbohydrates are easy for our gut to digest and do not create excess gas. In contrast, when we eat ‘fermentable carbohydrates,’ bacteria breaks them down in a process known as fermentation, producing excess gas.
Below are some examples of foods allowed and should be avoided on the diet (1).
Foods allowed on the low fermentation diet
- Sweet potato
- Regular potatoes
- Healthy fats
- Animal proteins
- Most fruits
- Some vegetables
- Protein powders (including vegan proteins)
Foods not allowed on the low fermentation diet;
- Beans and pulses
- Some dairy
- High FODMAP sweeteners
- Fiber supplements
Meal Patterns on the low fermentation diet
On the diet, it is advised that you at least a 4 hour gap between each time you eat and that you should not eat close to bedtime (1).
This is because the gut has a ‘cleaning process’ called the migrating motor complex or MMC. The is a type of nervous system reaction that sweeps your gut every so often to clean it out but it does not work if you are eating.
You can read more about the MMC is my article on fasting and gut health.
In theory, if you are a snacker and eat every hour of the day, this process does not work and could lead to or worsen bacterial overgrowth.
The MMC is said to more active at night, hence the no eating before bed time rule.
The research on the low fermentation diet
There is no research on this specific diet protocol yet but the elements of the diet are theories based on other areas of similar research.
The Dietitian Verdict
Some of the principles around the diet, such as avoiding fermentable carbohydrates and snacking are likely beneficial to those trying to manage SIBO symptoms.
We know from studies in IBS that an intake of fermentable carbohydrates increases hydrogen gas production in the gut (2).
The 4 hour gap between eating could also be beneficial to allow the gut to ‘clear’ itself. BUT I wouldn’t be so strict with this as the time we fast overnight could be adequate alone for this function, we just don’t know yet.
So, if someone was struggling with this element, it would not be my primary focus. BUT, if you are able to have 4 hours gaps between your meals without causing any real problems then why not try it would be my advice.
The concerns I would have with this is diet are the following;
- There is no research to suggest this protocol is useful in SIBO.
- There is no specific time suggested for the diet. When we know that SIBO can be caused by poor gut health it would be detrimental to suggest that someone should avoid fermentable carbohydrates (which are also prebiotic foods) for long-periods of time.
- Some of the ‘allowed foods’ contain high levels of fermentable carbohydrates such as vegan protein powders, sweet potato and mushrooms.
- It is a very restrictive diet and could cause nutritional deficiencies longer-term.
- It doesn’t address bowel function or gut health which are both issues that can cause SIBO.
Overall, this diet does have some good elements to it but I would advise anyone reading this that they only do this diet alongside a dietitian to prevent damage to their gut health.
The low fermentation diet is often recommended to manage SIBO symptoms but has not been researched before. The diet is also restrictive and information appears to be contradictory at times which may leave you confused and at risk of nutritional deficiencies.
I recommend that if you are diagnosed with SIBO that you should work with a GI doctor and dietitian team to have a more tailored approach for your symptoms. This tailored approach would look at reducing your SIBO symptoms and improving your gut health to help avoid repeated SIBO issues.
Kirsten Jackson is a UK registered Consultant Gastroenterology Dietitian and founder of The Food Treatment Clinic. She has undergone many qualifications to get where she is today, including a UK BSc Honours Degree in Dietetics and Post-Graduate Certificate in Advanced Dietetics. In addition to this, she has FODMAP Training from Kings College London University. Kirsten set up The Food Treatment Clinic in 2015 after first experiencing digestive problems herself. She felt that the NHS was unable to provide the support individuals needed and went on to specialise in this area before opening a bespoke IBS service. Kirsten also participates in charity work as an Expert Advisor for the IBS Network. In addition, she can be seen in publications such as Cosmopolitan and The Telegraph discussing IBS as an Official Media Spokesperson to the IBS Network.
Ts a very good summary on basics of Sibo Low Fermentation Diet. I have had GI issues for several years with what i call ” The GI Unknown Zone” quick diagnosis w typical offers of invasive endoscopy or colonoscopy offered in my opinion way too often If we are in fact “we are what we eat” i would think the best approach would be start w diet and general blood work w general gastro history( like bowel movement types) move from there before patient get procedures which many times leaves them still w little to no problem resolution. Here’s to the Dieticians feeding the humans and the billions of critters inside w consideration to all membersl :).
Kirsten Jackson Specialist Dietitian says
Thank you Em! We could not agree more! There are many unnecessary invasive tests going on and mostly any requirement for further testing would be shown in first line blood markers. We hope to raise awareness of this going forward. Thank you!
I’m confused. If I am vegan but eat fish 3 times a week, can I eat tofu or tempeh while on the Cedars-Sinai Low Fermentable Diet? Cedars Sinai Low Fermentation diet does not say, it just says no beans or legumes, but FODMAPs, that also excludes beans says tofu and tempeh or ok. Cedars Sinai Low Ferm diet works better for me than fodmaps, so could i include tofu and tempeh for protien?
Kirsten Jackson Specialist Dietitian says
Hi Gretchen, the cedars-sinai diet does not outline if this is allowed or not. However, we advise a low FODMAP diet and some forms of soy are allowed. You can find out more info on this here: Is Soy Low or High FODMAP?
Pamela szczesniak says
I have SIBO methan. I also have colitis which causes diarrhea sibi am never constipated. It states not to use fiber but i must. Why no fiber, fermantation?
Serena Bansal says
Hi Pamela! I am afraid we cannot give personalised advice without further assessment. If you would like help with this, please do not hesitate to email us on firstname.lastname@example.org.
Pat Armstrong says
I love your write up on the low fermentation diet and agree totally with your comments on concerns surrounding the diet. I have just cleared both hydrogen and methane sibo which led me to your page, looking for further info on low fermentation diet, this being paramount to prevent relapse. The diet suggested is very unhealthy and yes, mustn’t be followed very long, however, Dr Mark Pimentel suggests 3 months, this being the highest window for relapse. I just wish there was more information right now when I need it the most.