The last internal stop of our process is the large intestine or colon. The small intestines pass the remaining undigested material to the large intestine. Here it is stored and concentrated by absorbing water. The majority of our micro flora are also here – both beneficial and detrimental. Micro flora is also found in the small intestines and stomach.

Once again the internal environment changes as the colon is slightly acidic at 6.8. The large intestine is where sodium, potassium, other vitamins and minerals, and water are absorbed. Of that original seven liters of enzymes the remaining 1.5 liters is absorbed in the colon. Feces made here which are one third matter and two thirds water. A major part of the feces is dead bacteria. There are several pounds of flora in the bowel. The beneficial flora produce B Vitamins, Vitamin K, and will digest proteins.

We have 400 to 500 types of bacteria in our digestive system. This is often simplified as the “good” and the “bad” bacteria. To keep it simple the “good” bacteria are those that live on some of the undigested material and their waste products are vitamins that we can use. The “good” bacteria are called probiotics. The most prominent are: Lactobacilli (Lactobacillus acidophilus, Lactobacillus bulgaricus), Bifidobacterium, and Saccharomyces boulardi.

On the other hand the “bad” bacteria are those who live on other undigested material, mostly the sugar and other carbohydrates, and produce waste that is toxic to our system causing bloating, gas, and many of the other digestive disorders that we previously spoke of.

When we discuss our micro flora or bacteria think of it as continuous war with many battles. All the varieties are battling to survive. When you take an antibiotic (anti-life) it kills all the bacteria – both the good and the bad, but not yeast such as candida which takes over. This is why often have yeast infection after round of antibiotics.

There are a variety of food sources for the good bacteria. These include the cultured or fermented foods such as: yogurt, kefir, raw sauerkraut, kimchi, miso, tamari, and tempeh. Another source is probiotic supplements.

Bernard Rosen, PhD is a Nutrition Consultant and Educator. He works with individuals, groups, and at corporations to create individualized nutrition and wellness programs. He has offices in Coeur d’Alene, ID. To learn more or to schedule an appointment, e-mail at, call (208) 771-6570 or go to