Here is what it says on the page:
"Genesis Extruded Guinea Pig Food is a complete
food fortified based on fresh vegetative ingredients, fortified with essential amino acids, fatty acids, vitamin C and other essential vitamins and minerals all in a convenient effective extruded croquette.
Guinea pigs are simple-stomached herbivores with nutritional considerations much like that of the rabbit and rat. They require adequate levels of vegetative matter in their diet to promote cecal fermentation and rely upon coprophragy to support some essential vitamins and amino acids. They are also unique in their requirement for elevated vitamin C levels.
The Genesis Extruded Guinea Pig Food is produced with special attention to supporting the nutritional requirements of the guinea pig throughout all life stages. As noted above, this diet possesses sufficient vegetative fiber sources, probiotics, and prebiotics to promote good cecal fermentation, and adequate vitamin C to meet the unique needs of the guinea pig. The extrusion process assures that the grains and proteins used in the formulation are properly cooked for complete digestion, and that heat labile anti-nutritional factors such as the trypsin inhibitor are neutralized. This method of food delivery also assures that the guinea pig has adequate hard-fibrous food to support healthy tooth wear, and to encapsulate all the essential nutrients in every morsel."
And the main ingredient in those is timothy hay.
They are low in fat (2,5%)
And I even found a picture (although this is genesis for rabbits in the picture, but my new genesis pellets look the same)