1. If the stomach doesn't churn properly, there will be a lack of digestive juice, therefore poor absorption of minerals, leading to deficiency. 2. Lack of stomach acid also leads to poor protein digestion which is a contributing factor in allergies. 3. Weak stomach acid may not kill off organisms in food resulting in parasites or food poisoning. 4. Undersecretion of stomach juices can cause ulcers. 5. Lack of stomach acid can result in decreased peristalsis, leading to constipation and an overload of toxins.