A close relative of maltose is a molecule known as isomaltose (typically found in items such as beer and honey). The biggest difference between maltose and isomaltose is that isomaltose is joined together by an α-1,6 chemical bond, rather than an α-1,4 chemical bond. Scientists suspected that by adding a certain enzyme (transglucosidase) to high maltose syrup, they could change the bonds from α-1,4 to α-1,6, thereby making it more resistant to being broken down by the enzymes, as described above, when compared to maltose. Again, while this sounds excellent in theory, it is not necessarily what happens in our bodies. In fact, isomaltose (and thus, IMO syrups used in some of these products) is broken down by certain enzymes on the brush border of the small intestine. Though the α-1,6 bond breaks down slower compared to the α-1,4 bond, these IMO syrups, which often use a blend of di-and oligosaccharides, ultimately metabolize into small amounts of glucose and maltose and thus should be viewed as a slow digesting carbohydrate rather than a true fiber.
Skimping on fiber isn’t good for your digestive health, as it feeds the good bacteria in your GI tract, something that benefits you beyond adequate bowel movements. “The digestive tract is where your body’s second brain is, and it’s home to the majority of your immune system,” says Elia. “If you’re following keto, it should be one of your biggest priorities to make sure you get adequate fiber to keep your gut healthy and happy,” she adds. And, she notes, high-fat diets slow digestion and decrease GI motility, so it’s especially important to get enough.