It can be very confusing, but one needs to understand that optimal pH is highly dependent on which tissue/fluid you are talking about.
Optimal pH in the digestive tract begins in the mouth as slightly alkaline (but varies between 5-8) down into the stomach as highly acidic (1-3), into the duodenum as slightly acidic (5.5-6.5), after the pancreatic/biliary area and small intestine as slightly alkaline (7.0 - 7.5) and large intestine as acidic (6-6.5).
A pH change in these portions of the digestive track will create imbalances that end up in pathogen overgrowth and nutritional deficiencies.
Only when the pH of digestive tract is regulated the remaining tissues pH will be in balance, for it is the digestive track pH that allows the nutrients to be absorbed and waste to be properly regulated.
Certainly the most critical pH of the body is blood which is slightly alkaline and tightly control around 7.35-7.45, however it can only be regulated in that range when nutrients are present.
Food bound minerals are only available after being ionized by the acidic contents of the stomach. Only then will they be absorbed and allowed to be put to work.
The production of stomach acid is energetically uphill, meaning it takes a lot of effort and ATP molecules to produce it. Wrong food combining/ wrong diet (with excessive protein intake) and nutritional deficiencies can slow down the production of stomach acid). And stomach acid being the great enabler of digestion/nutrient absorption and antiseptic, a decrease on its availability is the starting point of most diseases (triggered by wrong diet of course).
So when candida is flourishing and other pathogens are running wild is because the digestive tract pH environment is out of whack. With this, we start seeing imbalances in other tissues because of the lack of nutrition and waste accumulation (originating from digestive tract malfunction).
My urine pH was highly alkaline, but certainly didnt mean I was healthy (calcium was being robbed from my bones to try to alkalize the blood/urine - due to mineral unavailability because of the lack of stomach acid).
Only when I started boosting my digestion is when the pH of different tissues began to normalize.
That's why I focus on the "acification" of the gut to ensure correct digestion and pH balance. When the stomach is acidic and happy, and snowball effect rolls down the GI tract and secretions, nutrient absorption will occur as it should.
Another important piece of the puzzle is proper functioning liver - a billiary blockage will result pH imbalance in the small intestine along with proper lipid breakdown. EFAs are critical for health and the short chain fatty acids (caprylic, butyric) are necessary for candida control and healthy intestinal flora. And when healthy intestinal flora is healthy it will allow the reuptake of nutrients like vitamin D, B12 blliary acids, whily producing a slew of B vitamins and vitamin K.
As to not leave the pancreas behind, it's malfunctioning/weakness typical results from the wrong diet that demands high levels of digestive enzymes and blood Sugar
regulators. Lack of stomach acid will always affect pancreas/liver secretions as they are controlled by chyme's pH.