Plaintains are otherwise known as cooking bananas and are banana cultivars in the genus Musa whose fruits are generally used in cooking.

They may be eaten while ripe or unripe and starchy.

Some plaintains are also referred to as green bananas.

Can guinea pigs eat plaintains?

We take a look in depth at their nutritional data and find out more.

In particular, their acidic, water, sugar, fat, salt, calcium, and phosphorus content is of most interest as far as guinea pigs are concerned.

Nutritional value per 100 g (3.5 oz)
Energy 510 kJ (120 kcal)
Carbohydrates
31.89 g
Sugars 15 g
Dietary fiber 2.3 g
Fat
0.37 g
Protein
1.3 g
Vitamins
Vitamin A equiv.
beta-carotene
(7%) 56 μg
(4%) 457 μg
Thiamine (B1) (5%) 0.052 mg
Riboflavin (B2) (5%) 0.054 mg
Niacin (B3) (5%) 0.686 mg
Pantothenic acid (B5) (5%) 0.26 mg
Vitamin B6 (23%) 0.299 mg
Folate (B9) (6%) 22 μg
Choline (3%) 13.5 mg
Vitamin C (22%) 18.4 mg
Vit E (1%) 0.14 mg
Vitamin K (1%) 0.7 μg
Minerals
Calcium (0%) 3 mg
Iron (5%) 0.6 mg
Magnesium (10%) 37 mg
Phosphorus (5%) 34 mg
Potassium (11%) 499 mg
Sodium (0%) 4 mg
Zinc (1%) 0.14 mg
Other constituents
Water 65.3 g

source wikipedia

As you can see, plaintains contain a huge amount of water, a hint of fat, salt and calcium, a little phosphorus, quite a lot of acidic content, and a lot of sugar.

This means that plaintains are not a good food for guinea pigs to eat.

They can have a nibble of them, but due to their high water and sugar content, they are not good for guinea pigs to have too much of them.

If anything, they are a food to avoid feeding piggies.