This is a pretty deep subject. It has to do with how you define your terms, and even the word biofilm I'm not sure I like that word.
I'll go into my history a little bit and some of the doctors that helped me as it relates to this term biofilm.
When I first got ill I started out with doctors and then on to nutritionists. The first nutrition doctor was basically what people would call paleo, but this was a bit before that term was coined. So he sort of indoctrinated me into this concept that modern foods (agrarian) were not really compatible with human chemistry and he had the most success with very strict meat and water diet with very little everything else. Caveat was that he did have some patients who did better with vegetables and brown rice, but not the majority. This was a very long time ago and a lot of new information has been written since then.
Anyway, I eliminated grains, milk (sometimes I cheated with cream), beans, preservatives , all processed food, and most fruit. I was sort of brainwashed by this guy but it helped tremendously as just a piece of bread would make me almost suicidal at that point.
So about 2 days after that my whole gut started changing and I started to pass these really dried out hard stools. And no this wasn't the meat I was eating as some people have tried to suggest. Meat does not turn rock hard in less than a day in the gut, maybe if you don't digest it and it sits there for 10 years it does.
I thought that this would be the answer to everything as the doctor was sort of a guru type guy. I did get more energy, and was able to get out of bed, and a lot of things got somewhat better. So this was the start of the reversal of what people call biofilm.
I was on this diet for about 7 years, eventually I started adding more carbs in as fruit, maybe a bit of rice and I did have ice cream, maybe I was addicted but it helped me a lot and I got some good energy. So it was more or less protein, fat and Sugar diet. Sticking to this I passed plaque for 7 years, almost non-stop every day.
I'll make a point here in hindsight that this diet, for me only, was food that I could digest very well compared to my previous diet which was a lot of milk and cereal, SAD diet or maybe a bit healthier. Maybe I was celiac and eliminating the gluten was the main factor.
For other people I know that meat and fat would destroy them, so let's just say that eating a diet that is specialized for the person is what would work, anything that you digest very well will most likely cause you to undergo a similar cleansing reaction - if your intestine are in fact full of plaque.
So people talk about this so called biofilm as if they are mainly clean inside but there is some mysterious organism making this film every day. I know that there are in fact some organisms that do produce protective enzymes and such, but I think that the main issue is improper diet for many years in the past. If your intestines are coated with layers and layers of waste it makes sense that you will not have a healthy mucosal layer and you will prone to any and all sorts of creatures living on the waste.
After 7-8 years for some reason I started to pass worms. I have no idea why it started, only guesses, but this went on for years and years and years. It was a living hell, like a lot of stories you read in the parasite forum. I had ascaris, strongyloides, flukes, ropes, and probably more. In between passing the parasites I'd keeping passing the mucoid plaque, and on and on in endless cycle.
I'm sure my case is extreme, or who knows maybe it's not so rare if people found the correct diet to reverse things. I'm two decades into the process with no end in sight as far as the plaque goes. I am not strict at all now, eat much more fruit, vegetables, very little meat, fair amount of fat, little grains. If I go strict with no grains, similar to the original diet outlined the plaque starts up again. there are a lot positives as I feel my absorption is really good now and it keeps getting better and better as time goes on, but it's a pretty difficult full time process.
I did a lot of other health things too, this is just a short little summary. In the very beginning my body was breaking down very rapidly and I had to eat a lot of protein to keep muscle on. Now it's the reverse and anything more than 2 ounces of protein seems to make me fat, low protein keeps the muscle on.
Currently my colon is inflamed, gas, bloating, and there are no parasites coming out, so I'm looking into the cause - maybe protozoa or I need to do something aggressive other than diet to get the plaque out of my colon.
So for the biofilm, I had my fillings out, I eat fermented foods, some prebiotic foods that have inulin, grain free, gluten free, very minimal processed foods, and mainly compatible foods for my biochemistry (probably different for everyone), and this is enough to keep the film from forming and to keep the right bacteria in my gut to clean things out. If I drank milk I would have biofilm and mucous constantly, and same with bread. I had also taken l. salivarus at one point, but I don't think it is necessary because I can get the same results just tweaking the diet as mentioned. Also how some foods are cooked makes a difference. Animal fat seems to be a neutral or maybe even helps the good bacteria. Bone broth would be a pretty strong cleanser.
This is all very similar to the gaps diet which is fairly recent. It's all like the lady says, you have to go slow at first because the cleansing can be really hard. It's been a very long battle for me with some returns, but not a victory. I think a lot of people would not go through all this and look for a different answer, in which case the term biofilm becomes more real.