(Select The Best) Fiberpsyll 4 in 1 may help prevent sand colic. Adds bulk fiber to the diet and provides digestive support. 4 in 1 formula contains psyllium, wheat bran and beet pulp for bulk fiber, plus probiotics (direct-fed-microbials), prebiotics (mannaoligysides) and live yeast to support digestion. Supportive enzymes benefit the digestive system, working in tandem for healthy digestion. Research has shown that providing microbial support greatly improves the removal of sand in the ventral cecum when compared to feeding psyllium alone. Psyllium has also been shown to help control blood glucose and insulin concentrations. Research has shown that supplementing with psyllium resulted in lower average blood glucose levels in horses after feeding.