Feeding rats a diet with 5% spirulina for 100 days (compared to a control group not fed spirulina) revealed: 1. the weight of the caecum increased 13%; 2. lactobacillus increased 327%; 3. vitamin B1 inside the caecum increased 43%. Since spirulina did not supply this additional B1, it improved overall B1 absorption. The study suggests eating spirulina increases lactobacillus and may increase efficient absorption of Vitamin B1 and other vitamins from the entire diet.