Fiber as a source of calories?

It seems to me that the more I learn, the more suprised I get with how common knowledge is wrong.

Common knowledge would tell you that fiber helps digestion, but that body cannot digest it, thus no calories.

However, new research says that bacteries in digestive system actually ferment fiber and convert it into fatty acids.

Thus, essentially, fiber gets fermented into calories by digestive system, and adds more to energy value of food.

Eating 30 grams of fiber adds about 200 calories. Research suggests 10% of our calories come from fiber.

It's interesting that in theory, fiber should help prevent and treat constipation. However, the evidence shows that this advice does not work for everyone.  While some studies show that adding fiber to your diet may improve your symptoms, other studies show that reducing your intake is best. 

Beans are high in fiber.

..." Beans are the cornerstone of every Blue Zones diet in the world: black beans in Nicoya; lentils, garbanzo, and white beans in the Mediterranean; and soybeans in Okinawa. The long-lived populations in these blue zones eat at least four times as many beans as we do, on average. One five-country study, financed by the World Health Organization, found that eating 20 grams of beans daily reduced a person’s risk of dying in any given year by about 8%."...

Chia seeds are also good. You can pretty much add them to everything. I add them to my fruit smoothies for example.  

Sieg heil mein Fuhrer.

Ze fibre is good for ze goosesteppen.