Also known as The mung or moong bean, green gram or golden gram, is grown mainly in India, China, Thailand, Philippines, Indonesia, Burma, Bangladesh, Vietnam, Laos and Cambodia, but also in hot and dry regions of Southern Europe and the Southern United States.
It is a food that is used as an ingredient in both savory and sweet dishes.
So if we can eat it, can guinea pigs eat mung bean sprouts and if they can how much of it can be eaten?

Lets take a look at their nutritional data and find out more about this vegetable?
As per usual, we’re particularly interested in its calcium, phosphorus, fat, sugar, and acidic content.
Energyt126 kJ (30 kcal)
Carbohydratest5.94 g
– Sugarst4.13 g
– Dietary fibert1.8 g
Fatt0.18 g
Proteint3.04 g
Thiamine (vit. B1)t0.084 mg (7%)
Riboflavin (vit. B2)t0.124 mg (10%)
Niacin (vit. B3)t0.749 mg (5%)
Pantothenic acid (B5)t0.38 mg (8%)
Vitamin B6t0.088 mg (7%)
Folate (vit. B9)t61 μg (15%)
Vitamin Ct13.2 mg (16%)
Vitamin Et0.1 mg (1%)
Vitamin Kt33 μg (31%)
Calciumt13 mg (1%)
Iront0.91 mg (7%)
Magnesiumt21 mg (6%)
Manganeset0.188 mg (9%)
Phosphorust54 mg (8%)
Potassiumt149 mg (3%)
Zinct0.41 mg (4%)

(source: Wikipedia)
As you can see mung bean sprouts contain a little phosphorus, a hint of calcium, they are quite acidic, have a hint of fat and some sugar in them. They also contain some vitamin c.
Based on the information about, mung bean sprouts can be eaten by guinea pigs, but only once or twice a week due to their acidic content.