Your gut is your second brain and second skin.
"Its main role is controlling digestion, from swallowing to the release of enzymes that break down food to the control of blood flow that helps with nutrient absorption to elimination.”(John Hopkins)
The gut is also where a large percentage of your brain hormones are produce. The health of your gut will have a large role in anxiety and depression.
Combining certain foods can lead to digestive problems such as "decreased nutrient assimilation, intestinal gas, abdominal pain, swelling, constipation, contaminated blood, and mental fog".(the whole journey)
One of the most simple and important rules of food combining is to eat fruit by itself. If you do mix fruit with other foods, never combine fruit with carbohydrates. Example of Carbs: Grains, Potatoes, Bread or Legumes.
By avoiding this combination bloating and gas will be minimized. Fruit and carbohydrates have a similar digestion rate, so they, in turn, compete with one another. The carb will win and digest first, and the fruit ferments while it waits its turn to be digested.
Other Rules for Easiest Digestion:
Melon – Eat it alone.
Avocados, rich fat, are best combined with green vegetables.
Tomatoes are best eaten with non-starchy vegetables and proteins.
Eat fruit at least 30 minutes before a meal or 1 1/2 hours after.
Here is the full food combining chart.